Vulnerability-Lookup

CVE-2026-75806 (GCVE-0-2026-75806)

Vulnerability from cvelistv5 – Published: 2026-09-29 15:32 – Updated: 2026-09-29 16:53

Title

Unauthenticated and Undersized DTLS 1.2 AEAD Record Causes DoS

Summary

Issue summary: An established DTLS 1.2 association using an AEAD cipher suite can be terminated by a single unauthenticated datagram whose encrypted fragment is shorter than the mandatory explicit IV and authentication tag overhead. Impact summary: An attacker who can send a datagram that is routed to an existing DTLS 1.2 association can tear that association down without knowing any key material. This is a Denial of Service limited to the targeted association. There is no memory safety or confidentiality impact. CWE: CWE-1284: Improper Validation of Specified Quantity in Input Description: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher suite carries an explicit IV followed by the ciphertext and an authentication tag. When decrypting such a record the record layer passed the record length to the cipher implementation before checking that the record was long enough to contain the explicit IV and the tag. For a record shorter than that overhead the cipher implementation rejected the impossible length, and the record layer treated this as an internal failure and raised a fatal internal_error alert instead of treating the record as one that failed authentication. In TLS 1.2 the same record causes a fatal internal_error alert instead of the expected bad_record_mac alert. Since any undecryptable record already terminates a TLS connection, this is a protocol conformance issue rather than a security issue in TLS. The fix validates the record length against the explicit IV and tag length before any AEAD processing, so that TLS reports bad_record_mac and DTLS silently discards the record. FIPS impact: no The affected code is outside the FIPS module boundary.

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-29 16:52 UTC

CWE

CWE-1284 - Improper Validation of Specified Quantity in Input

Assigner

openssl mitre root

References

5 references

URL	Tags
https://openssl-library.org/news/secadv/20260929.txt	vendor-advisory
https://github.com/openssl/openssl/commit/04728a2…	patch
https://github.com/openssl/openssl/commit/050b275…	patch
https://github.com/openssl/openssl/commit/3a4589d…	patch
https://github.com/openssl/openssl/commit/5af82fe…	patch

Impacted products

1 product

Vendor	Product	Version	CPE status
OpenSSL	OpenSSL	Affected: 4.0.0 , < 4.0.3 (semver) Affected: 3.6.0 , < 3.6.5 (semver) Affected: 3.5.0 , < 3.5.9 (semver) Affected: 3.4.0 , < 3.4.8 (semver) Affected: 3.0.0 , < 3.0.23 (semver) Affected: 1.1.1 , < 1.1.1zj (custom)	guessed

Date Public

2026-09-29 14:21

Credits

Mounir Idrassi Mounir Idrassi

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "LOW",
              "baseScore": 5.3,
              "baseSeverity": "MEDIUM",
              "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:L",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-75806",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-29T16:52:47.298458Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-29T16:53:23.785Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "OpenSSL",
          "vendor": "OpenSSL",
          "versions": [
            {
              "lessThan": "4.0.3",
              "status": "affected",
              "version": "4.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.6.5",
              "status": "affected",
              "version": "3.6.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.5.9",
              "status": "affected",
              "version": "3.5.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.4.8",
              "status": "affected",
              "version": "3.4.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.0.23",
              "status": "affected",
              "version": "3.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.1.1zj",
              "status": "affected",
              "version": "1.1.1",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Mounir Idrassi"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Mounir Idrassi"
        }
      ],
      "datePublic": "2026-09-29T14:21:57.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\u003cbr\u003ecan be terminated by a single unauthenticated datagram whose encrypted\u003cbr\u003efragment is shorter than the mandatory explicit IV and authentication tag\u003cbr\u003eoverhead.\u003cbr\u003e\u003cbr\u003eImpact summary: An attacker who can send a datagram that is routed to an\u003cbr\u003eexisting DTLS 1.2 association can tear that association down without knowing\u003cbr\u003eany key material. This is a Denial of Service limited to the targeted\u003cbr\u003eassociation. There is no memory safety or confidentiality impact.\u003cbr\u003e\u003cbr\u003eCWE: CWE-1284: Improper Validation of Specified Quantity in Input\u003cbr\u003e\u003cbr\u003eDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\u003cbr\u003esuite carries an explicit IV followed by the ciphertext and an authentication\u003cbr\u003etag. When decrypting such a record the record layer passed the record length to\u003cbr\u003ethe cipher implementation before checking that the record was long enough to\u003cbr\u003econtain the explicit IV and the tag. For a record shorter than that overhead the\u003cbr\u003ecipher implementation rejected the impossible length, and the record layer\u003cbr\u003etreated this as an internal failure and raised a fatal internal_error alert\u003cbr\u003einstead of treating the record as one that failed authentication.\u003cbr\u003e\u003cbr\u003eIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\u003cbr\u003eexpected bad_record_mac alert. Since any undecryptable record already\u003cbr\u003eterminates a TLS connection, this is a protocol conformance issue rather than\u003cbr\u003ea security issue in TLS.\u003cbr\u003e\u003cbr\u003eThe fix validates the record length against the explicit IV and tag length\u003cbr\u003ebefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\u003cbr\u003esilently discards the record.\u003cbr\u003e\u003cbr\u003eFIPS impact: no\u003cbr\u003eThe affected code is outside the FIPS module boundary."
            }
          ],
          "value": "Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\ncan be terminated by a single unauthenticated datagram whose encrypted\nfragment is shorter than the mandatory explicit IV and authentication tag\noverhead.\n\nImpact summary: An attacker who can send a datagram that is routed to an\nexisting DTLS 1.2 association can tear that association down without knowing\nany key material. This is a Denial of Service limited to the targeted\nassociation. There is no memory safety or confidentiality impact.\n\nCWE: CWE-1284: Improper Validation of Specified Quantity in Input\n\nDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\nsuite carries an explicit IV followed by the ciphertext and an authentication\ntag. When decrypting such a record the record layer passed the record length to\nthe cipher implementation before checking that the record was long enough to\ncontain the explicit IV and the tag. For a record shorter than that overhead the\ncipher implementation rejected the impossible length, and the record layer\ntreated this as an internal failure and raised a fatal internal_error alert\ninstead of treating the record as one that failed authentication.\n\nIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\nexpected bad_record_mac alert. Since any undecryptable record already\nterminates a TLS connection, this is a protocol conformance issue rather than\na security issue in TLS.\n\nThe fix validates the record length against the explicit IV and tag length\nbefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\nsilently discards the record.\n\nFIPS impact: no\nThe affected code is outside the FIPS module boundary."
        }
      ],
      "metrics": [
        {
          "format": "other",
          "other": {
            "content": {
              "text": "Low"
            },
            "type": "https://openssl-library.org/policies/general/security-policy/"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1284",
              "description": "CWE-1284 Improper Validation of Specified Quantity in Input",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-29T15:32:21.457Z",
        "orgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5",
        "shortName": "openssl"
      },
      "references": [
        {
          "name": "OpenSSL Advisory",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://openssl-library.org/news/secadv/20260929.txt"
        },
        {
          "name": "4.0.3 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d"
        },
        {
          "name": "3.6.5 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972"
        },
        {
          "name": "3.5.9 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d"
        },
        {
          "name": "3.4.8 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Unauthenticated and Undersized DTLS 1.2 AEAD Record Causes DoS",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5",
    "assignerShortName": "openssl",
    "cveId": "CVE-2026-75806",
    "datePublished": "2026-09-29T15:32:21.457Z",
    "dateReserved": "2026-08-18T09:34:32.659Z",
    "dateUpdated": "2026-09-29T16:53:23.785Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "OpenSSL",
                "vendor": "OpenSSL",
                "versions": [
                  {
                    "lessThan": "4.0.3",
                    "status": "affected",
                    "version": "4.0.0",
                    "versionType": "semver"
                  },
                  {
                    "lessThan": "3.6.5",
                    "status": "affected",
                    "version": "3.6.0",
                    "versionType": "semver"
                  },
                  {
                    "lessThan": "3.5.9",
                    "status": "affected",
                    "version": "3.5.0",
                    "versionType": "semver"
                  },
                  {
                    "lessThan": "3.4.8",
                    "status": "affected",
                    "version": "3.4.0",
                    "versionType": "semver"
                  },
                  {
                    "lessThan": "3.0.23",
                    "status": "affected",
                    "version": "3.0.0",
                    "versionType": "semver"
                  },
                  {
                    "lessThan": "1.1.1zj",
                    "status": "affected",
                    "version": "1.1.1",
                    "versionType": "custom"
                  }
                ]
              }
            ],
            "source": "openssl-security@openssl.org"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\ncan be terminated by a single unauthenticated datagram whose encrypted\nfragment is shorter than the mandatory explicit IV and authentication tag\noverhead.\n\nImpact summary: An attacker who can send a datagram that is routed to an\nexisting DTLS 1.2 association can tear that association down without knowing\nany key material. This is a Denial of Service limited to the targeted\nassociation. There is no memory safety or confidentiality impact.\n\nCWE: CWE-1284: Improper Validation of Specified Quantity in Input\n\nDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\nsuite carries an explicit IV followed by the ciphertext and an authentication\ntag. When decrypting such a record the record layer passed the record length to\nthe cipher implementation before checking that the record was long enough to\ncontain the explicit IV and the tag. For a record shorter than that overhead the\ncipher implementation rejected the impossible length, and the record layer\ntreated this as an internal failure and raised a fatal internal_error alert\ninstead of treating the record as one that failed authentication.\n\nIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\nexpected bad_record_mac alert. Since any undecryptable record already\nterminates a TLS connection, this is a protocol conformance issue rather than\na security issue in TLS.\n\nThe fix validates the record length against the explicit IV and tag length\nbefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\nsilently discards the record.\n\nFIPS impact: no\nThe affected code is outside the FIPS module boundary."
          }
        ],
        "id": "CVE-2026-75806",
        "lastModified": "2026-09-29T21:27:41.130",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "LOW",
                "baseScore": 5.3,
                "baseSeverity": "MEDIUM",
                "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:L",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 1.4,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-75806",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-29T16:52:47.298458Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-09-29T16:17:11.217",
        "references": [
          {
            "source": "openssl-security@openssl.org",
            "url": "https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d"
          },
          {
            "source": "openssl-security@openssl.org",
            "url": "https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972"
          },
          {
            "source": "openssl-security@openssl.org",
            "url": "https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d"
          },
          {
            "source": "openssl-security@openssl.org",
            "url": "https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d"
          },
          {
            "source": "openssl-security@openssl.org",
            "url": "https://openssl-library.org/news/secadv/20260929.txt"
          }
        ],
        "sourceIdentifier": "openssl-security@openssl.org",
        "vulnStatus": "Awaiting Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-1284"
              }
            ],
            "source": "openssl-security@openssl.org",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-29T17:32:45+00:00",
      "cve": "CVE-2026-75806",
      "id": "CVE-2026-75806",
      "initial_release_date": "2026-09-29T15:32:21.457000+00:00",
      "product_status:known_affected": "89",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "openssl: OpenSSL: Denial of Service via undersized DTLS record",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-75806.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "NETWORK",
                  "availabilityImpact": "LOW",
                  "baseScore": 5.3,
                  "baseSeverity": "MEDIUM",
                  "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:L",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-75806",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-09-29T16:52:47.298458Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-09-29T16:53:20.190Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "product": "OpenSSL",
              "vendor": "OpenSSL",
              "versions": [
                {
                  "lessThan": "4.0.3",
                  "status": "affected",
                  "version": "4.0.0",
                  "versionType": "semver"
                },
                {
                  "lessThan": "3.6.5",
                  "status": "affected",
                  "version": "3.6.0",
                  "versionType": "semver"
                },
                {
                  "lessThan": "3.5.9",
                  "status": "affected",
                  "version": "3.5.0",
                  "versionType": "semver"
                },
                {
                  "lessThan": "3.4.8",
                  "status": "affected",
                  "version": "3.4.0",
                  "versionType": "semver"
                },
                {
                  "lessThan": "3.0.23",
                  "status": "affected",
                  "version": "3.0.0",
                  "versionType": "semver"
                },
                {
                  "lessThan": "1.1.1zj",
                  "status": "affected",
                  "version": "1.1.1",
                  "versionType": "custom"
                }
              ]
            }
          ],
          "credits": [
            {
              "lang": "en",
              "type": "reporter",
              "value": "Mounir Idrassi"
            },
            {
              "lang": "en",
              "type": "remediation developer",
              "value": "Mounir Idrassi"
            }
          ],
          "datePublic": "2026-09-29T14:21:57.000Z",
          "descriptions": [
            {
              "lang": "en",
              "supportingMedia": [
                {
                  "base64": false,
                  "type": "text/html",
                  "value": "Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\u003cbr\u003ecan be terminated by a single unauthenticated datagram whose encrypted\u003cbr\u003efragment is shorter than the mandatory explicit IV and authentication tag\u003cbr\u003eoverhead.\u003cbr\u003e\u003cbr\u003eImpact summary: An attacker who can send a datagram that is routed to an\u003cbr\u003eexisting DTLS 1.2 association can tear that association down without knowing\u003cbr\u003eany key material. This is a Denial of Service limited to the targeted\u003cbr\u003eassociation. There is no memory safety or confidentiality impact.\u003cbr\u003e\u003cbr\u003eCWE: CWE-1284: Improper Validation of Specified Quantity in Input\u003cbr\u003e\u003cbr\u003eDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\u003cbr\u003esuite carries an explicit IV followed by the ciphertext and an authentication\u003cbr\u003etag. When decrypting such a record the record layer passed the record length to\u003cbr\u003ethe cipher implementation before checking that the record was long enough to\u003cbr\u003econtain the explicit IV and the tag. For a record shorter than that overhead the\u003cbr\u003ecipher implementation rejected the impossible length, and the record layer\u003cbr\u003etreated this as an internal failure and raised a fatal internal_error alert\u003cbr\u003einstead of treating the record as one that failed authentication.\u003cbr\u003e\u003cbr\u003eIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\u003cbr\u003eexpected bad_record_mac alert. Since any undecryptable record already\u003cbr\u003eterminates a TLS connection, this is a protocol conformance issue rather than\u003cbr\u003ea security issue in TLS.\u003cbr\u003e\u003cbr\u003eThe fix validates the record length against the explicit IV and tag length\u003cbr\u003ebefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\u003cbr\u003esilently discards the record.\u003cbr\u003e\u003cbr\u003eFIPS impact: no\u003cbr\u003eThe affected code is outside the FIPS module boundary."
                }
              ],
              "value": "Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\ncan be terminated by a single unauthenticated datagram whose encrypted\nfragment is shorter than the mandatory explicit IV and authentication tag\noverhead.\n\nImpact summary: An attacker who can send a datagram that is routed to an\nexisting DTLS 1.2 association can tear that association down without knowing\nany key material. This is a Denial of Service limited to the targeted\nassociation. There is no memory safety or confidentiality impact.\n\nCWE: CWE-1284: Improper Validation of Specified Quantity in Input\n\nDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\nsuite carries an explicit IV followed by the ciphertext and an authentication\ntag. When decrypting such a record the record layer passed the record length to\nthe cipher implementation before checking that the record was long enough to\ncontain the explicit IV and the tag. For a record shorter than that overhead the\ncipher implementation rejected the impossible length, and the record layer\ntreated this as an internal failure and raised a fatal internal_error alert\ninstead of treating the record as one that failed authentication.\n\nIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\nexpected bad_record_mac alert. Since any undecryptable record already\nterminates a TLS connection, this is a protocol conformance issue rather than\na security issue in TLS.\n\nThe fix validates the record length against the explicit IV and tag length\nbefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\nsilently discards the record.\n\nFIPS impact: no\nThe affected code is outside the FIPS module boundary."
            }
          ],
          "metrics": [
            {
              "format": "other",
              "other": {
                "content": {
                  "text": "Low"
                },
                "type": "https://openssl-library.org/policies/general/security-policy/"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-1284",
                  "description": "CWE-1284 Improper Validation of Specified Quantity in Input",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-09-29T15:32:21.457Z",
            "orgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5",
            "shortName": "openssl"
          },
          "references": [
            {
              "name": "OpenSSL Advisory",
              "tags": [
                "vendor-advisory"
              ],
              "url": "https://openssl-library.org/news/secadv/20260929.txt"
            },
            {
              "name": "4.0.3 git commit",
              "tags": [
                "patch"
              ],
              "url": "https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d"
            },
            {
              "name": "3.6.5 git commit",
              "tags": [
                "patch"
              ],
              "url": "https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972"
            },
            {
              "name": "3.5.9 git commit",
              "tags": [
                "patch"
              ],
              "url": "https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d"
            },
            {
              "name": "3.4.8 git commit",
              "tags": [
                "patch"
              ],
              "url": "https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d"
            }
          ],
          "source": {
            "discovery": "UNKNOWN"
          },
          "title": "Unauthenticated and Undersized DTLS 1.2 AEAD Record Causes DoS",
          "x_generator": {
            "engine": "Vulnogram 0.2.0"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5",
        "assignerShortName": "openssl",
        "cveId": "CVE-2026-75806",
        "datePublished": "2026-09-29T15:32:21.457Z",
        "dateReserved": "2026-08-18T09:34:32.659Z",
        "dateUpdated": "2026-09-29T16:53:23.785Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

FKIE_CVE-2026-75806

Vulnerability from fkie_nvd - Published: 2026-09-29 16:17 - Updated: 2026-09-29 21:27

Severity

5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Summary

References

	URL	Tags
	openssl-security@openssl.org	https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d
	openssl-security@openssl.org	https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972
	openssl-security@openssl.org	https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d
	openssl-security@openssl.org	https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d
	openssl-security@openssl.org	https://openssl-library.org/news/secadv/20260929.txt

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "OpenSSL",
          "vendor": "OpenSSL",
          "versions": [
            {
              "lessThan": "4.0.3",
              "status": "affected",
              "version": "4.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.6.5",
              "status": "affected",
              "version": "3.6.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.5.9",
              "status": "affected",
              "version": "3.5.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.4.8",
              "status": "affected",
              "version": "3.4.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.0.23",
              "status": "affected",
              "version": "3.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.1.1zj",
              "status": "affected",
              "version": "1.1.1",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "openssl-security@openssl.org"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\ncan be terminated by a single unauthenticated datagram whose encrypted\nfragment is shorter than the mandatory explicit IV and authentication tag\noverhead.\n\nImpact summary: An attacker who can send a datagram that is routed to an\nexisting DTLS 1.2 association can tear that association down without knowing\nany key material. This is a Denial of Service limited to the targeted\nassociation. There is no memory safety or confidentiality impact.\n\nCWE: CWE-1284: Improper Validation of Specified Quantity in Input\n\nDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\nsuite carries an explicit IV followed by the ciphertext and an authentication\ntag. When decrypting such a record the record layer passed the record length to\nthe cipher implementation before checking that the record was long enough to\ncontain the explicit IV and the tag. For a record shorter than that overhead the\ncipher implementation rejected the impossible length, and the record layer\ntreated this as an internal failure and raised a fatal internal_error alert\ninstead of treating the record as one that failed authentication.\n\nIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\nexpected bad_record_mac alert. Since any undecryptable record already\nterminates a TLS connection, this is a protocol conformance issue rather than\na security issue in TLS.\n\nThe fix validates the record length against the explicit IV and tag length\nbefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\nsilently discards the record.\n\nFIPS impact: no\nThe affected code is outside the FIPS module boundary."
    }
  ],
  "id": "CVE-2026-75806",
  "lastModified": "2026-09-29T21:27:41.130",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "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:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-75806",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-29T16:52:47.298458Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-29T16:17:11.217",
  "references": [
    {
      "source": "openssl-security@openssl.org",
      "url": "https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d"
    },
    {
      "source": "openssl-security@openssl.org",
      "url": "https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972"
    },
    {
      "source": "openssl-security@openssl.org",
      "url": "https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d"
    },
    {
      "source": "openssl-security@openssl.org",
      "url": "https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d"
    },
    {
      "source": "openssl-security@openssl.org",
      "url": "https://openssl-library.org/news/secadv/20260929.txt"
    }
  ],
  "sourceIdentifier": "openssl-security@openssl.org",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1284"
        }
      ],
      "source": "openssl-security@openssl.org",
      "type": "Secondary"
    }
  ]
}

GHSA-4H8F-FWPC-HWWF

Vulnerability from github – Published: 2026-09-29 18:31 – Updated: 2026-09-29 18:31

Details

Impact summary: An attacker who can send a datagram that is routed to an existing DTLS 1.2 association can tear that association down without knowing any key material. This is a Denial of Service limited to the targeted association. There is no memory safety or confidentiality impact.

CWE: CWE-1284: Improper Validation of Specified Quantity in Input

Description: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher suite carries an explicit IV followed by the ciphertext and an authentication tag. When decrypting such a record the record layer passed the record length to the cipher implementation before checking that the record was long enough to contain the explicit IV and the tag. For a record shorter than that overhead the cipher implementation rejected the impossible length, and the record layer treated this as an internal failure and raised a fatal internal_error alert instead of treating the record as one that failed authentication.

In TLS 1.2 the same record causes a fatal internal_error alert instead of the expected bad_record_mac alert. Since any undecryptable record already terminates a TLS connection, this is a protocol conformance issue rather than a security issue in TLS.

The fix validates the record length against the explicit IV and tag length before any AEAD processing, so that TLS reports bad_record_mac and DTLS silently discards the record.

FIPS impact: no The affected code is outside the FIPS module boundary.

Severity

5.3 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-75806"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1284"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-29T16:17:11Z",
    "severity": "MODERATE"
  },
  "details": "Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\ncan be terminated by a single unauthenticated datagram whose encrypted\nfragment is shorter than the mandatory explicit IV and authentication tag\noverhead.\n\nImpact summary: An attacker who can send a datagram that is routed to an\nexisting DTLS 1.2 association can tear that association down without knowing\nany key material. This is a Denial of Service limited to the targeted\nassociation. There is no memory safety or confidentiality impact.\n\nCWE: CWE-1284: Improper Validation of Specified Quantity in Input\n\nDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\nsuite carries an explicit IV followed by the ciphertext and an authentication\ntag. When decrypting such a record the record layer passed the record length to\nthe cipher implementation before checking that the record was long enough to\ncontain the explicit IV and the tag. For a record shorter than that overhead the\ncipher implementation rejected the impossible length, and the record layer\ntreated this as an internal failure and raised a fatal internal_error alert\ninstead of treating the record as one that failed authentication.\n\nIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\nexpected bad_record_mac alert. Since any undecryptable record already\nterminates a TLS connection, this is a protocol conformance issue rather than\na security issue in TLS.\n\nThe fix validates the record length against the explicit IV and tag length\nbefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\nsilently discards the record.\n\nFIPS impact: no\nThe affected code is outside the FIPS module boundary.",
  "id": "GHSA-4h8f-fwpc-hwwf",
  "modified": "2026-09-29T18:31:44Z",
  "published": "2026-09-29T18:31:44Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-75806"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d"
    },
    {
      "type": "WEB",
      "url": "https://openssl-library.org/news/secadv/20260929.txt"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-75806 (GCVE-0-2026-75806)

FKIE_CVE-2026-75806

GHSA-4H8F-FWPC-HWWF

Tags

Sightings

Nomenclature

Related by attack behaviour