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CVE-2026-63495 (GCVE-0-2026-63495)

Vulnerability from nvd – Published: 2026-08-20 17:49 – Updated: 2026-08-20 19:17

Title

Libevent: Unbounded memory accumulation in WebSocket server via fragmented frames

Summary

Libevent is an event notification library. From 2.2.0-alpha-dev until 2.2.2-alpha, the libevent WebSocket server in ws.c accumulates fragmented frames in evws->incomplete_frames without enforcing a total message-size limit. An unauthenticated remote client can repeatedly send fragmented WebSocket frames below WS_MAX_RECV_FRAME_SZ with FIN=0, causing the evbuffer to grow without bound until the process or host exhausts memory. This issue is fixed in version 2.2.2-alpha.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 19:16 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption
CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/291c4…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha-dev, < 2.2.2-alpha

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-63495",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-20T19:16:58.376889Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-20T19:17:04.616Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha-dev, \u003c 2.2.2-alpha"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. From 2.2.0-alpha-dev until 2.2.2-alpha, the libevent WebSocket server in ws.c accumulates fragmented frames in evws-\u003eincomplete_frames without enforcing a total message-size limit. An unauthenticated remote client can repeatedly send fragmented WebSocket frames below WS_MAX_RECV_FRAME_SZ with FIN=0, causing the evbuffer to grow without bound until the process or host exhausts memory. This issue is fixed in version 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:49:16.790Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/291c4d1cd75695e898030ebd5c4ddf26c094077b",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/291c4d1cd75695e898030ebd5c4ddf26c094077b"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-qx89-wf2v-vgmx",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: Unbounded memory accumulation in WebSocket server via fragmented frames"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63495",
    "datePublished": "2026-08-20T17:49:16.790Z",
    "dateReserved": "2026-07-16T21:49:52.069Z",
    "dateUpdated": "2026-08-20T19:17:04.616Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-63388 (GCVE-0-2026-63388)

Vulnerability from nvd – Published: 2026-08-20 17:44 – Updated: 2026-08-20 17:44

Title

Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a heap out-of-bounds write in bufferevent_sock.c when bufferevent_socket_set_conn_address_ copies a kernel-supplied AF_UNIX peer address into bufferevent_private.conn_address. Release builds compiled with NDEBUG disable the EVUTIL_ASSERT length guard, and the evhttp accept path can pass a 110-byte sockaddr from accept() into the 28-byte field. An unauthenticated local peer able to connect to an AF_UNIX listener can overwrite the adjacent dns_request pointer and heap data, causing memory corruption with confidentiality, integrity, and availability impact. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

8.4 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE

CWE-617 - Reachable Assertion
CWE-787 - Out-of-bounds Write

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/52057…	x_refsource_MISC
https://github.com/libevent/libevent/commit/ef38f…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: < 2.1.13 Affected: >= 2.2.0-alpha, < 2.2.2-alpha

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a heap out-of-bounds write in bufferevent_sock.c when bufferevent_socket_set_conn_address_ copies a kernel-supplied AF_UNIX peer address into bufferevent_private.conn_address. Release builds compiled with NDEBUG disable the EVUTIL_ASSERT length guard, and the evhttp accept path can pass a 110-byte sockaddr from accept() into the 28-byte field. An unauthenticated local peer able to connect to an AF_UNIX listener can overwrite the adjacent dns_request pointer and heap data, causing memory corruption with confidentiality, integrity, and availability impact. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 8.4,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-617",
              "description": "CWE-617: Reachable Assertion",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787: Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:44:18.435Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-cvq5-vrvr-j338",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63388",
    "datePublished": "2026-08-20T17:44:18.435Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
    "dateUpdated": "2026-08-20T17:44:18.435Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-63387 (GCVE-0-2026-63387)

Vulnerability from nvd – Published: 2026-08-20 17:53 – Updated: 2026-08-20 17:53

Title

Libevent: Off-by-one stack buffer overflow in dnsname_to_labels via crafted DNS server response

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an off-by-one stack buffer overflow in evdns.c when dnsname_to_labels formats a name-bearing DNS record at the end of the 64 KB stack buffer allocated by evdns_server_request_format_response. The final-label check permits j plus label_len plus one to equal buf_len, after which the terminating null byte is written to buf[buf_len]. A crafted DNS server response containing PTR, CNAME, MX, NS, or SOA data can trigger the one-byte out-of-bounds write and crash or corrupt the process. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

7 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

CWE

CWE-121 - Stack-based Buffer Overflow
CWE-193 - Off-by-one Error
CWE-787 - Out-of-bounds Write

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            },
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an off-by-one stack buffer overflow in evdns.c when dnsname_to_labels formats a name-bearing DNS record at the end of the 64 KB stack buffer allocated by evdns_server_request_format_response. The final-label check permits j plus label_len plus one to equal buf_len, after which the terminating null byte is written to buf[buf_len]. A crafted DNS server response containing PTR, CNAME, MX, NS, or SOA data can trigger the one-byte out-of-bounds write and crash or corrupt the process. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-121",
              "description": "CWE-121: Stack-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-193",
              "description": "CWE-193: Off-by-one Error",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787: Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:53:41.863Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-58rx-7448-jw47",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-58rx-7448-jw47"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-58rx-7448-jw47",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: Off-by-one stack buffer overflow in dnsname_to_labels via crafted DNS server response"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63387",
    "datePublished": "2026-08-20T17:53:41.863Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
    "dateUpdated": "2026-08-20T17:53:41.863Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-63385 (GCVE-0-2026-63385)

Vulnerability from nvd – Published: 2026-08-20 17:55 – Updated: 2026-08-20 17:55

Title

Libevent: HTTP header handling bugs create risk of access control bypass.

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause downstream C string operations to truncate a path and bypass validation performed on a different representation. evhttp_header_is_valid_value also accepts obsolete line folding in header values containing carriage return or line feed characters, allowing a proxy and libevent to interpret headers differently and enabling header injection or access control bypass. The CRLF header acceptance is fixed in versions 2.1.13 and 2.2.2-alpha, but the reviewed patches do not clearly remediate the URI NUL-truncation condition.

Severity

9.2 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/758be…	x_refsource_MISC
https://github.com/libevent/libevent/commit/9170d…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            },
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause downstream C string operations to truncate a path and bypass validation performed on a different representation. evhttp_header_is_valid_value also accepts obsolete line folding in header values containing carriage return or line feed characters, allowing a proxy and libevent to interpret headers differently and enabling header injection or access control bypass. The CRLF header acceptance is fixed in versions 2.1.13 and 2.2.2-alpha, but the reviewed patches do not clearly remediate the URI NUL-truncation condition."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 9.2,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "LOW",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:55:36.214Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2"
        },
        {
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CVE-2026-63384 (GCVE-0-2026-63384)

Vulnerability from nvd – Published: 2026-08-20 17:53 – Updated: 2026-08-20 19:50

Title

Libevent: `evtag_unmarshal_header()` decodes a wire `uint32` length into a signed `int` return value.

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an incorrect integer conversion in event_tagging.c when evtag_unmarshal_header uses evtag_decode_int to decode an attacker-controlled uint32 payload length and returns it as a signed int. Values above INT_MAX become negative or truncated, and evtag_unmarshal_string can use the converted value in allocation sizing, producing a wrapped large allocation request and denial of service. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 19:50 UTC

CWE

CWE-190 - Integer Overflow or Wraparound

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/109c1…	x_refsource_MISC
https://github.com/libevent/libevent/commit/5e3c6…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

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CVE-2026-63383 (GCVE-0-2026-63383)

Vulnerability from nvd – Published: 2026-08-20 17:48 – Updated: 2026-08-20 18:41

Title

Libevent: decode_tag_internal() can lead to out-of-bounds read

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent can read beyond a contiguous evbuffer region in event_tagging.c when decode_tag_internal requests at most five bytes from evbuffer_pullup but iterates using the full logical buffer length. A fragmented evbuffer containing a six-byte malformed tag can therefore advance past the pullup window and trigger an out-of-bounds read, which can crash a process that decodes attacker-controlled tagged RPC data. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 18:37 UTC

CWE

CWE-125 - Out-of-bounds Read

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/91ed8…	x_refsource_MISC
https://github.com/libevent/libevent/commit/e1f9e…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

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CVE-2026-63382 (GCVE-0-2026-63382)

Vulnerability from nvd – Published: 2026-08-20 17:51 – Updated: 2026-08-20 19:33

Title

libevent evhttp: Multiple HTTP Parser Bugs Enable Request Smuggling

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, the libevent evhttp parser in http.c inconsistently handles duplicate Transfer-Encoding headers, comma-separated Transfer-Encoding values, and bare line feeds in chunked framing. evhttp_find_header can select only the first header, evhttp_check_transfer_encoding_ was absent so the previous whole-string comparison fails to recognize valid lists ending in chunked, and evhttp_handle_chunked_read uses EVBUFFER_EOL_CRLF rather than EVBUFFER_EOL_CRLF_STRICT, accepting bare LF chunk terminators. When libevent is deployed behind a proxy that frames the same request differently, an unauthenticated remote attacker can desynchronize request boundaries and smuggle a second request, potentially bypassing access controls or poisoning caches. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

9.2 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 19:33 UTC

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

GitHub_M mitre root

References

7 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/10abb…	x_refsource_MISC
https://github.com/libevent/libevent/commit/5119c…	x_refsource_MISC
https://github.com/libevent/libevent/commit/83ba6…	x_refsource_MISC
https://github.com/libevent/libevent/commit/ac387…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

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          "url": "https://github.com/libevent/libevent/commit/5119ceb00557bf007f9065709e852686f3c0bb6e"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/83ba67373032334559b82409db035dd8c3cc1660",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/83ba67373032334559b82409db035dd8c3cc1660"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/ac38703b2d312200c4f967f02936af0118d384a0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/ac38703b2d312200c4f967f02936af0118d384a0"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-q39v-w2g7-gr8j",
        "discovery": "UNKNOWN"
      },
      "title": "libevent evhttp: Multiple HTTP Parser Bugs Enable Request Smuggling"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63382",
    "datePublished": "2026-08-20T17:51:15.156Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
    "dateUpdated": "2026-08-20T19:33:50.217Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-63381 (GCVE-0-2026-63381)

Vulnerability from nvd – Published: 2026-08-20 17:50 – Updated: 2026-08-20 17:50

Title

Libevent: Dangling Pointer in `evbuffer_add_buffer_reference`

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a use-after-free in buffer.c when evbuffer_add_buffer_reference processes an output buffer whose out_total_len is zero. evbuffer_free_all_chains frees the initial empty chain without resetting outbuf->first, outbuf->last, or outbuf->last_with_datap, and APPEND_CHAIN_MULTICAST subsequently dereferences the dangling chain pointer. A caller that can drive this buffer state can cause memory corruption or a process crash. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

5.8 (Medium)


                        
                          CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

CWE

CWE-908 - Use of Uninitialized Resource

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/5cb95…	x_refsource_MISC
https://github.com/libevent/libevent/commit/9db09…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            },
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a use-after-free in buffer.c when evbuffer_add_buffer_reference processes an output buffer whose out_total_len is zero. evbuffer_free_all_chains frees the initial empty chain without resetting outbuf-\u003efirst, outbuf-\u003elast, or outbuf-\u003elast_with_datap, and APPEND_CHAIN_MULTICAST subsequently dereferences the dangling chain pointer. A caller that can drive this buffer state can cause memory corruption or a process crash. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 5.8,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-908",
              "description": "CWE-908: Use of Uninitialized Resource",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:50:09.322Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-c2pj-cg4r-88c8",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-c2pj-cg4r-88c8"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/5cb95ba2f804f8aff46f88d58391c71e1251cd1c",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/5cb95ba2f804f8aff46f88d58391c71e1251cd1c"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/9db091b04f569be3a700fa9860ef02f90b830af9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/9db091b04f569be3a700fa9860ef02f90b830af9"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-c2pj-cg4r-88c8",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: Dangling Pointer in `evbuffer_add_buffer_reference`"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63381",
    "datePublished": "2026-08-20T17:50:09.322Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
    "dateUpdated": "2026-08-20T17:50:09.322Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-63380 (GCVE-0-2026-63380)

Vulnerability from nvd – Published: 2026-08-20 17:52 – Updated: 2026-08-20 17:52

Title

Libevent: Null Pointer Dereference in `evws_new_session`

Summary

Libevent is an event notification library. Prior to 2.2.2-alpha, libevent can dereference invalid list pointers in ws.c when evws_new_session enters its error path after evhttp_start_ws_ succeeds but bufferevent_enable_locking_ fails. evws_connection_free sees a non-null http_server and unconditionally calls TAILQ_REMOVE even though the session was never inserted into http_server->ws_sessions. A local caller able to induce this allocation or locking failure can crash the process. This issue is fixed in version 2.2.2-alpha.

Severity

5.7 (Medium)


                        
                          CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CWE

CWE-416 - Use After Free
CWE-476 - NULL Pointer Dereference

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/825c1…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: < 2.2.2-alpha

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.2.2-alpha"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.2.2-alpha, libevent can dereference invalid list pointers in ws.c when evws_new_session enters its error path after evhttp_start_ws_ succeeds but bufferevent_enable_locking_ fails. evws_connection_free sees a non-null http_server and unconditionally calls TAILQ_REMOVE even though the session was never inserted into http_server-\u003ews_sessions. A local caller able to induce this allocation or locking failure can crash the process. This issue is fixed in version 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 5.7,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-416",
              "description": "CWE-416: Use After Free",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-476",
              "description": "CWE-476: NULL Pointer Dereference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:52:29.458Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-3rpf-frgx-xq34",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: Null Pointer Dereference in `evws_new_session`"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63380",
    "datePublished": "2026-08-20T17:52:29.458Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
    "dateUpdated": "2026-08-20T17:52:29.458Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-63379 (GCVE-0-2026-63379)

Vulnerability from nvd – Published: 2026-08-20 17:55 – Updated: 2026-08-20 17:55

Title

Libevent: HTTP Header smuggling

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent processes chunked HTTP trailers in http.c through evhttp_read_trailer and merges them into request headers. The fix introduces evhttp_parse_headers_impl_ and a temporary trailer header list. An unauthenticated remote attacker can place security-sensitive fields in trailers so that an upstream proxy and the libevent application interpret different effective headers, enabling header smuggling, authorization bypass, proxy-header spoofing, or cache poisoning. The fix parses trailers into a temporary header list and discards them instead of merging them into req->input_headers. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/87e8e…	x_refsource_MISC
https://github.com/libevent/libevent/commit/b8470…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: < 2.1.13 Affected: >= 2.2.0-alpha, < 2.2.2-alpha

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent processes chunked HTTP trailers in http.c through evhttp_read_trailer and merges them into request headers. The fix introduces evhttp_parse_headers_impl_ and a temporary trailer header list. An unauthenticated remote attacker can place security-sensitive fields in trailers so that an upstream proxy and the libevent application interpret different effective headers, enabling header smuggling, authorization bypass, proxy-header spoofing, or cache poisoning. The fix parses trailers into a temporary header list and discards them instead of merging them into req-\u003einput_headers. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:55:00.789Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-2gmv-p5m7-98p6",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-2gmv-p5m7-98p6"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aefa1636",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aefa1636"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a4c485",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a4c485"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-2gmv-p5m7-98p6",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: HTTP Header smuggling"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63379",
    "datePublished": "2026-08-20T17:55:00.789Z",
    "dateReserved": "2026-07-16T17:39:30.170Z",
    "dateUpdated": "2026-08-20T17:55:00.789Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-63385 (GCVE-0-2026-63385)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:55 – Updated: 2026-08-20 17:55

Title

Libevent: HTTP header handling bugs create risk of access control bypass.

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause downstream C string operations to truncate a path and bypass validation performed on a different representation. evhttp_header_is_valid_value also accepts obsolete line folding in header values containing carriage return or line feed characters, allowing a proxy and libevent to interpret headers differently and enabling header injection or access control bypass. The CRLF header acceptance is fixed in versions 2.1.13 and 2.2.2-alpha, but the reviewed patches do not clearly remediate the URI NUL-truncation condition.

Severity

9.2 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/758be…	x_refsource_MISC
https://github.com/libevent/libevent/commit/9170d…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            },
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause downstream C string operations to truncate a path and bypass validation performed on a different representation. evhttp_header_is_valid_value also accepts obsolete line folding in header values containing carriage return or line feed characters, allowing a proxy and libevent to interpret headers differently and enabling header injection or access control bypass. The CRLF header acceptance is fixed in versions 2.1.13 and 2.2.2-alpha, but the reviewed patches do not clearly remediate the URI NUL-truncation condition."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 9.2,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "LOW",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:55:36.214Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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      },
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          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/758be0c0f69c1934ef9a84ab39e9f9e5fde2e6d0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/758be0c0f69c1934ef9a84ab39e9f9e5fde2e6d0"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/9170dd35e64714613e8d13b290587cfc28e258e2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/9170dd35e64714613e8d13b290587cfc28e258e2"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
            "x_refsource_MISC"
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        },
        {
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          "tags": [
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        }
      ],
      "source": {
        "advisory": "GHSA-jcwh-pvf2-73p2",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: HTTP header handling bugs create risk of access control bypass."
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63385",
    "datePublished": "2026-08-20T17:55:36.214Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
    "dateUpdated": "2026-08-20T17:55:36.214Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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}

CVE-2026-63379 (GCVE-0-2026-63379)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:55 – Updated: 2026-08-20 17:55

Title

Libevent: HTTP Header smuggling

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent processes chunked HTTP trailers in http.c through evhttp_read_trailer and merges them into request headers. The fix introduces evhttp_parse_headers_impl_ and a temporary trailer header list. An unauthenticated remote attacker can place security-sensitive fields in trailers so that an upstream proxy and the libevent application interpret different effective headers, enabling header smuggling, authorization bypass, proxy-header spoofing, or cache poisoning. The fix parses trailers into a temporary header list and discards them instead of merging them into req->input_headers. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/87e8e…	x_refsource_MISC
https://github.com/libevent/libevent/commit/b8470…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: < 2.1.13 Affected: >= 2.2.0-alpha, < 2.2.2-alpha

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
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          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent processes chunked HTTP trailers in http.c through evhttp_read_trailer and merges them into request headers. The fix introduces evhttp_parse_headers_impl_ and a temporary trailer header list. An unauthenticated remote attacker can place security-sensitive fields in trailers so that an upstream proxy and the libevent application interpret different effective headers, enabling header smuggling, authorization bypass, proxy-header spoofing, or cache poisoning. The fix parses trailers into a temporary header list and discards them instead of merging them into req-\u003einput_headers. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          }
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        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
              "lang": "en",
              "type": "CWE"
            }
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          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-2gmv-p5m7-98p6",
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          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-2gmv-p5m7-98p6"
        },
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          "name": "https://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aefa1636",
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            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aefa1636"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a4c485",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a4c485"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
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        "advisory": "GHSA-2gmv-p5m7-98p6",
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      },
      "title": "Libevent: HTTP Header smuggling"
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    "dateReserved": "2026-07-16T17:39:30.170Z",
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  },
  "dataType": "CVE_RECORD",
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}

CVE-2026-63387 (GCVE-0-2026-63387)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:53 – Updated: 2026-08-20 17:53

Title

Libevent: Off-by-one stack buffer overflow in dnsname_to_labels via crafted DNS server response

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an off-by-one stack buffer overflow in evdns.c when dnsname_to_labels formats a name-bearing DNS record at the end of the 64 KB stack buffer allocated by evdns_server_request_format_response. The final-label check permits j plus label_len plus one to equal buf_len, after which the terminating null byte is written to buf[buf_len]. A crafted DNS server response containing PTR, CNAME, MX, NS, or SOA data can trigger the one-byte out-of-bounds write and crash or corrupt the process. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

7 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

CWE

CWE-121 - Stack-based Buffer Overflow
CWE-193 - Off-by-one Error
CWE-787 - Out-of-bounds Write

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            },
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an off-by-one stack buffer overflow in evdns.c when dnsname_to_labels formats a name-bearing DNS record at the end of the 64 KB stack buffer allocated by evdns_server_request_format_response. The final-label check permits j plus label_len plus one to equal buf_len, after which the terminating null byte is written to buf[buf_len]. A crafted DNS server response containing PTR, CNAME, MX, NS, or SOA data can trigger the one-byte out-of-bounds write and crash or corrupt the process. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
            "version": "3.1"
          }
        }
      ],
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          "descriptions": [
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              "cweId": "CWE-121",
              "description": "CWE-121: Stack-based Buffer Overflow",
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              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-193",
              "description": "CWE-193: Off-by-one Error",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787: Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:53:41.863Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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      },
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        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-58rx-7448-jw47",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-58rx-7448-jw47"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
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            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
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      ],
      "source": {
        "advisory": "GHSA-58rx-7448-jw47",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: Off-by-one stack buffer overflow in dnsname_to_labels via crafted DNS server response"
    }
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    "assignerShortName": "GitHub_M",
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  "dataType": "CVE_RECORD",
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}

CVE-2026-63384 (GCVE-0-2026-63384)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:53 – Updated: 2026-08-20 19:50

Title

Libevent: `evtag_unmarshal_header()` decodes a wire `uint32` length into a signed `int` return value.

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an incorrect integer conversion in event_tagging.c when evtag_unmarshal_header uses evtag_decode_int to decode an attacker-controlled uint32 payload length and returns it as a signed int. Values above INT_MAX become negative or truncated, and evtag_unmarshal_string can use the converted value in allocation sizing, producing a wrapped large allocation request and denial of service. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 19:50 UTC

CWE

CWE-190 - Integer Overflow or Wraparound

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/109c1…	x_refsource_MISC
https://github.com/libevent/libevent/commit/5e3c6…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-63384",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-20T19:50:07.634809Z",
                "version": "2.0.3"
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              "type": "ssvc"
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        "providerMetadata": {
          "dateUpdated": "2026-08-20T19:50:32.085Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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        "references": [
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            "tags": [
              "exploit"
            ],
            "url": "https://github.com/libevent/libevent/security/advisories/GHSA-45c6-qx49-89m8"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
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          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
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              "version": "\u003c 2.1.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an incorrect integer conversion in event_tagging.c when evtag_unmarshal_header uses evtag_decode_int to decode an attacker-controlled uint32 payload length and returns it as a signed int. Values above INT_MAX become negative or truncated, and evtag_unmarshal_string can use the converted value in allocation sizing, producing a wrapped large allocation request and denial of service. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
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      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
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            "subAvailabilityImpact": "NONE",
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            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
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          "tags": [
            "x_refsource_MISC"
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          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
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      ],
      "source": {
        "advisory": "GHSA-45c6-qx49-89m8",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: `evtag_unmarshal_header()` decodes a wire `uint32` length into a signed `int` return value."
    }
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  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63384",
    "datePublished": "2026-08-20T17:53:08.417Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
    "dateUpdated": "2026-08-20T19:50:32.085Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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}

CVE-2026-63380 (GCVE-0-2026-63380)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:52 – Updated: 2026-08-20 17:52

Title

Libevent: Null Pointer Dereference in `evws_new_session`

Summary

Libevent is an event notification library. Prior to 2.2.2-alpha, libevent can dereference invalid list pointers in ws.c when evws_new_session enters its error path after evhttp_start_ws_ succeeds but bufferevent_enable_locking_ fails. evws_connection_free sees a non-null http_server and unconditionally calls TAILQ_REMOVE even though the session was never inserted into http_server->ws_sessions. A local caller able to induce this allocation or locking failure can crash the process. This issue is fixed in version 2.2.2-alpha.

Severity

5.7 (Medium)


                        
                          CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CWE

CWE-416 - Use After Free
CWE-476 - NULL Pointer Dereference

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/825c1…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: < 2.2.2-alpha

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.2.2-alpha, libevent can dereference invalid list pointers in ws.c when evws_new_session enters its error path after evhttp_start_ws_ succeeds but bufferevent_enable_locking_ fails. evws_connection_free sees a non-null http_server and unconditionally calls TAILQ_REMOVE even though the session was never inserted into http_server-\u003ews_sessions. A local caller able to induce this allocation or locking failure can crash the process. This issue is fixed in version 2.2.2-alpha."
        }
      ],
      "metrics": [
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          "cvssV4_0": {
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
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            "baseScore": 5.7,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
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            "vectorString": "CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-416",
              "description": "CWE-416: Use After Free",
              "lang": "en",
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            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-476",
              "description": "CWE-476: NULL Pointer Dereference",
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:52:29.458Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34",
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          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34"
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          "tags": [
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            "x_refsource_MISC"
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          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
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      "source": {
        "advisory": "GHSA-3rpf-frgx-xq34",
        "discovery": "UNKNOWN"
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CVE-2026-63382 (GCVE-0-2026-63382)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:51 – Updated: 2026-08-20 19:33

Title

libevent evhttp: Multiple HTTP Parser Bugs Enable Request Smuggling

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, the libevent evhttp parser in http.c inconsistently handles duplicate Transfer-Encoding headers, comma-separated Transfer-Encoding values, and bare line feeds in chunked framing. evhttp_find_header can select only the first header, evhttp_check_transfer_encoding_ was absent so the previous whole-string comparison fails to recognize valid lists ending in chunked, and evhttp_handle_chunked_read uses EVBUFFER_EOL_CRLF rather than EVBUFFER_EOL_CRLF_STRICT, accepting bare LF chunk terminators. When libevent is deployed behind a proxy that frames the same request differently, an unauthenticated remote attacker can desynchronize request boundaries and smuggle a second request, potentially bypassing access controls or poisoning caches. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

9.2 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 19:33 UTC

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

GitHub_M mitre root

References

7 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/10abb…	x_refsource_MISC
https://github.com/libevent/libevent/commit/5119c…	x_refsource_MISC
https://github.com/libevent/libevent/commit/83ba6…	x_refsource_MISC
https://github.com/libevent/libevent/commit/ac387…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-63382",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-20T19:33:43.608585Z",
                "version": "2.0.3"
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            "tags": [
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            "url": "https://github.com/libevent/libevent/security/advisories/GHSA-q39v-w2g7-gr8j"
          }
        ],
        "title": "CISA ADP Vulnrichment"
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          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
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            },
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            }
          ]
        }
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      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, the libevent evhttp parser in http.c inconsistently handles duplicate Transfer-Encoding headers, comma-separated Transfer-Encoding values, and bare line feeds in chunked framing. evhttp_find_header can select only the first header, evhttp_check_transfer_encoding_ was absent so the previous whole-string comparison fails to recognize valid lists ending in chunked, and evhttp_handle_chunked_read uses EVBUFFER_EOL_CRLF rather than EVBUFFER_EOL_CRLF_STRICT, accepting bare LF chunk terminators. When libevent is deployed behind a proxy that frames the same request differently, an unauthenticated remote attacker can desynchronize request boundaries and smuggle a second request, potentially bypassing access controls or poisoning caches. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 9.2,
            "baseSeverity": "CRITICAL",
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              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
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              "type": "CWE"
            }
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          "url": "https://github.com/libevent/libevent/commit/5119ceb00557bf007f9065709e852686f3c0bb6e"
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          "name": "https://github.com/libevent/libevent/commit/ac38703b2d312200c4f967f02936af0118d384a0",
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          "url": "https://github.com/libevent/libevent/commit/ac38703b2d312200c4f967f02936af0118d384a0"
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          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
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          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
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      "title": "libevent evhttp: Multiple HTTP Parser Bugs Enable Request Smuggling"
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CVE-2026-63381 (GCVE-0-2026-63381)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:50 – Updated: 2026-08-20 17:50

Title

Libevent: Dangling Pointer in `evbuffer_add_buffer_reference`

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a use-after-free in buffer.c when evbuffer_add_buffer_reference processes an output buffer whose out_total_len is zero. evbuffer_free_all_chains frees the initial empty chain without resetting outbuf->first, outbuf->last, or outbuf->last_with_datap, and APPEND_CHAIN_MULTICAST subsequently dereferences the dangling chain pointer. A caller that can drive this buffer state can cause memory corruption or a process crash. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

5.8 (Medium)


                        
                          CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

CWE

CWE-908 - Use of Uninitialized Resource

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/5cb95…	x_refsource_MISC
https://github.com/libevent/libevent/commit/9db09…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            },
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            }
          ]
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      ],
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        {
          "lang": "en",
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        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 5.8,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
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          "descriptions": [
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              "description": "CWE-908: Use of Uninitialized Resource",
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          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-c2pj-cg4r-88c8"
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          "url": "https://github.com/libevent/libevent/commit/9db091b04f569be3a700fa9860ef02f90b830af9"
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          "tags": [
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CVE-2026-63495 (GCVE-0-2026-63495)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:49 – Updated: 2026-08-20 19:17

Title

Libevent: Unbounded memory accumulation in WebSocket server via fragmented frames

Summary

Libevent is an event notification library. From 2.2.0-alpha-dev until 2.2.2-alpha, the libevent WebSocket server in ws.c accumulates fragmented frames in evws->incomplete_frames without enforcing a total message-size limit. An unauthenticated remote client can repeatedly send fragmented WebSocket frames below WS_MAX_RECV_FRAME_SZ with FIN=0, causing the evbuffer to grow without bound until the process or host exhausts memory. This issue is fixed in version 2.2.2-alpha.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 19:16 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption
CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/291c4…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha-dev, < 2.2.2-alpha

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-63495",
                "options": [
                  {
                    "Exploitation": "poc"
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                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-20T19:16:58.376889Z",
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          "lang": "en",
          "value": "Libevent is an event notification library. From 2.2.0-alpha-dev until 2.2.2-alpha, the libevent WebSocket server in ws.c accumulates fragmented frames in evws-\u003eincomplete_frames without enforcing a total message-size limit. An unauthenticated remote client can repeatedly send fragmented WebSocket frames below WS_MAX_RECV_FRAME_SZ with FIN=0, causing the evbuffer to grow without bound until the process or host exhausts memory. This issue is fixed in version 2.2.2-alpha."
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            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:49:16.790Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/291c4d1cd75695e898030ebd5c4ddf26c094077b",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/291c4d1cd75695e898030ebd5c4ddf26c094077b"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-qx89-wf2v-vgmx",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: Unbounded memory accumulation in WebSocket server via fragmented frames"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63495",
    "datePublished": "2026-08-20T17:49:16.790Z",
    "dateReserved": "2026-07-16T21:49:52.069Z",
    "dateUpdated": "2026-08-20T19:17:04.616Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-63383 (GCVE-0-2026-63383)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:48 – Updated: 2026-08-20 18:41

Title

Libevent: decode_tag_internal() can lead to out-of-bounds read

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent can read beyond a contiguous evbuffer region in event_tagging.c when decode_tag_internal requests at most five bytes from evbuffer_pullup but iterates using the full logical buffer length. A fragmented evbuffer containing a six-byte malformed tag can therefore advance past the pullup window and trigger an out-of-bounds read, which can crash a process that decodes attacker-controlled tagged RPC data. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 18:37 UTC

CWE

CWE-125 - Out-of-bounds Read

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/91ed8…	x_refsource_MISC
https://github.com/libevent/libevent/commit/e1f9e…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: >= 2.2.0-alpha, < 2.2.2-alpha Affected: < 2.1.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-63383",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-20T18:37:55.514994Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-20T18:41:23.897Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/libevent/libevent/security/advisories/GHSA-fj29-64w6-73h6"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            },
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent can read beyond a contiguous evbuffer region in event_tagging.c when decode_tag_internal requests at most five bytes from evbuffer_pullup but iterates using the full logical buffer length. A fragmented evbuffer containing a six-byte malformed tag can therefore advance past the pullup window and trigger an out-of-bounds read, which can crash a process that decodes attacker-controlled tagged RPC data. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "CWE-125: Out-of-bounds Read",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:48:24.568Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-fj29-64w6-73h6",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-fj29-64w6-73h6"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/91ed8745eebabdd27592a83d350338a8c4626321",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/91ed8745eebabdd27592a83d350338a8c4626321"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/e1f9e21887c6b104e206a718385ba3ffc75180cb",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/e1f9e21887c6b104e206a718385ba3ffc75180cb"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
            "x_refsource_MISC"
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          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-fj29-64w6-73h6",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: decode_tag_internal() can lead to out-of-bounds read"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63383",
    "datePublished": "2026-08-20T17:48:24.568Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
    "dateUpdated": "2026-08-20T18:41:23.897Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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}

CVE-2026-63388 (GCVE-0-2026-63388)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:44 – Updated: 2026-08-20 17:44

Title

Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept

Summary

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a heap out-of-bounds write in bufferevent_sock.c when bufferevent_socket_set_conn_address_ copies a kernel-supplied AF_UNIX peer address into bufferevent_private.conn_address. Release builds compiled with NDEBUG disable the EVUTIL_ASSERT length guard, and the evhttp accept path can pass a 110-byte sockaddr from accept() into the 28-byte field. An unauthenticated local peer able to connect to an AF_UNIX listener can overwrite the adjacent dns_request pointer and heap data, causing memory corruption with confidentiality, integrity, and availability impact. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Severity

8.4 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE

CWE-617 - Reachable Assertion
CWE-787 - Out-of-bounds Write

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/libevent/libevent/security/adv…	x_refsource_CONFIRM
https://github.com/libevent/libevent/commit/52057…	x_refsource_MISC
https://github.com/libevent/libevent/commit/ef38f…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC
https://github.com/libevent/libevent/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libevent	libevent	Affected: < 2.1.13 Affected: >= 2.2.0-alpha, < 2.2.2-alpha

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "libevent",
          "vendor": "libevent",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.1.13"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.2.0-alpha, \u003c 2.2.2-alpha"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a heap out-of-bounds write in bufferevent_sock.c when bufferevent_socket_set_conn_address_ copies a kernel-supplied AF_UNIX peer address into bufferevent_private.conn_address. Release builds compiled with NDEBUG disable the EVUTIL_ASSERT length guard, and the evhttp accept path can pass a 110-byte sockaddr from accept() into the 28-byte field. An unauthenticated local peer able to connect to an AF_UNIX listener can overwrite the adjacent dns_request pointer and heap data, causing memory corruption with confidentiality, integrity, and availability impact. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 8.4,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-617",
              "description": "CWE-617: Reachable Assertion",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787: Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-20T17:44:18.435Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9"
        },
        {
          "name": "https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
          "tags": [
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          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
        },
        {
          "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
        }
      ],
      "source": {
        "advisory": "GHSA-cvq5-vrvr-j338",
        "discovery": "UNKNOWN"
      },
      "title": "Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-63388",
    "datePublished": "2026-08-20T17:44:18.435Z",
    "dateReserved": "2026-07-16T17:39:30.171Z",
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    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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}

Find a vulnerability

Search criteria ⓘ Use this form to refine search results.
Full-text search supports keyword queries with ranking and filtering.
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20 vulnerabilities found for libevent by libevent

CVE-2026-63495 (GCVE-0-2026-63495)

CVE-2026-63388 (GCVE-0-2026-63388)

CVE-2026-63387 (GCVE-0-2026-63387)

CVE-2026-63385 (GCVE-0-2026-63385)

CVE-2026-63384 (GCVE-0-2026-63384)

CVE-2026-63383 (GCVE-0-2026-63383)

CVE-2026-63382 (GCVE-0-2026-63382)

CVE-2026-63381 (GCVE-0-2026-63381)

CVE-2026-63380 (GCVE-0-2026-63380)

CVE-2026-63379 (GCVE-0-2026-63379)

CVE-2026-63385 (GCVE-0-2026-63385)

CVE-2026-63379 (GCVE-0-2026-63379)

CVE-2026-63387 (GCVE-0-2026-63387)

CVE-2026-63384 (GCVE-0-2026-63384)

CVE-2026-63380 (GCVE-0-2026-63380)

CVE-2026-63382 (GCVE-0-2026-63382)

CVE-2026-63381 (GCVE-0-2026-63381)

CVE-2026-63495 (GCVE-0-2026-63495)

CVE-2026-63383 (GCVE-0-2026-63383)

CVE-2026-63388 (GCVE-0-2026-63388)

Find a vulnerability

Search criteria ⓘ Use this form to refine search results. Full-text search supports keyword queries with ranking and filtering. You can combine vendor, product, and sources to narrow results. Enable “Apply ordering” to sort by date instead of relevance.

20 vulnerabilities found for libevent by libevent

CVE-2026-63495 (GCVE-0-2026-63495)

CVE-2026-63388 (GCVE-0-2026-63388)

CVE-2026-63387 (GCVE-0-2026-63387)

CVE-2026-63385 (GCVE-0-2026-63385)

CVE-2026-63384 (GCVE-0-2026-63384)

CVE-2026-63383 (GCVE-0-2026-63383)

CVE-2026-63382 (GCVE-0-2026-63382)

CVE-2026-63381 (GCVE-0-2026-63381)

CVE-2026-63380 (GCVE-0-2026-63380)

CVE-2026-63379 (GCVE-0-2026-63379)

CVE-2026-63385 (GCVE-0-2026-63385)

CVE-2026-63379 (GCVE-0-2026-63379)

CVE-2026-63387 (GCVE-0-2026-63387)

CVE-2026-63384 (GCVE-0-2026-63384)

CVE-2026-63380 (GCVE-0-2026-63380)

CVE-2026-63382 (GCVE-0-2026-63382)

CVE-2026-63381 (GCVE-0-2026-63381)

CVE-2026-63495 (GCVE-0-2026-63495)

CVE-2026-63383 (GCVE-0-2026-63383)

CVE-2026-63388 (GCVE-0-2026-63388)

Search criteria ⓘ Use this form to refine search results.
Full-text search supports keyword queries with ranking and filtering.
You can combine vendor, product, and sources to narrow results.
Enable “Apply ordering” to sort by date instead of relevance.