Vulnerability-Lookup

ubuntu-cve-2026-8711

Vulnerability from osv_ubuntu

Published

2026-05-19 15:16

Modified

2026-06-17 22:30

Summary

Details

NGINX JavaScript has a vulnerability when the js_fetch_proxy directive is configured with at least one client-controlled NGINX variable (for example, $http_, $arg_, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Severity

8.1 (High)


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

9.8 (Critical)


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

9.2 (Critical)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-8711	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-8711	REPORT
	https://my.f5.com/manage/s/article/K000161307	REPORT
	https://ubuntu.com/security/notices/USN-8425-1	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libnginx-mod-http-js",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "libnginx-mod-stream-js",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "njs",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "libnginx-mod-js",
        "purl": "pkg:deb/ubuntu/libnginx-mod-js@0.9.4-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.4-1ubuntu0.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.1-1ubuntu2",
        "0.9.1-1ubuntu3",
        "0.9.4-1~build1",
        "0.9.4-1",
        "0.9.4-1build1",
        "0.9.4-1build2"
      ]
    }
  ],
  "aliases": [],
  "details": "NGINX JavaScript has a vulnerability when the js_fetch_proxy\u00a0directive is configured with at least one client-controlled NGINX variable (for example, $http_*, $arg_*, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.",
  "id": "UBUNTU-CVE-2026-8711",
  "modified": "2026-06-17T22:30:05Z",
  "published": "2026-05-19T15:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-8711"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-8711"
    },
    {
      "type": "REPORT",
      "url": "https://my.f5.com/manage/s/article/K000161307"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8425-1"
    }
  ],
  "related": [
    "USN-8425-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-8711"
  ]
}

CVE-2026-8711 (GCVE-0-2026-8711)

Vulnerability from cvelistv5 – Published: 2026-05-19 14:04 – Updated: 2026-05-21 18:29 X_F5

Title

NGINX JavaScript vulnerability

Summary

NGINX JavaScript has a vulnerability when the js_fetch_proxy directive is configured with at least one client-controlled NGINX variable (for example, $http_*, $arg_*, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Severity

8.1 (High)


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

9.2 (Critical)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

References

1 reference

URL	Tags
https://my.f5.com/manage/s/article/K000161307	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
F5	NGINX JavaScript	Affected: 0.9.4 , < 0.9.9 (custom)

Date Public

2026-05-19 14:00

Credits

"F5 acknowledges udolemi (S2W) for bringing this issue to our attention and following the highest standards of coordinated disclosure."

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-8711",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-19T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-20T03:55:39.626Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "modules": [
            "ngx_http_js_module"
          ],
          "product": "NGINX JavaScript",
          "vendor": "F5",
          "versions": [
            {
              "lessThan": "0.9.9",
              "status": "affected",
              "version": "0.9.4",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "\"F5 acknowledges udolemi (S2W) for bringing this issue to our attention and following the highest standards of coordinated disclosure.\""
        }
      ],
      "datePublic": "2026-05-19T14:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eNGINX JavaScript has a vulnerability when the \u003c/span\u003e\u003cstrong\u003ejs_fetch_proxy\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\u0026nbsp;directive is configured with at least one client-controlled NGINX variable (for example, \u003c/span\u003e\u003cstrong\u003e$http_*\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e, \u003c/span\u003e\u003cstrong\u003e$arg_*\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e, \u003c/span\u003e\u003cstrong\u003e$cookie_*\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.\u003c/span\u003e \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
            }
          ],
          "value": "NGINX JavaScript has a vulnerability when the js_fetch_proxy\u00a0directive is configured with at least one client-controlled NGINX variable (for example, $http_*, $arg_*, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 9.2,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-122",
              "description": "CWE-122 Heap-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-21T18:29:16.674Z",
        "orgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab",
        "shortName": "f5"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://my.f5.com/manage/s/article/K000161307"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "tags": [
        "x_F5"
      ],
      "title": "NGINX JavaScript vulnerability",
      "x_generator": {
        "engine": "F5 SIRTBot v1.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab",
    "assignerShortName": "f5",
    "cveId": "CVE-2026-8711",
    "datePublished": "2026-05-19T14:04:18.860Z",
    "dateReserved": "2026-05-15T20:10:29.764Z",
    "dateUpdated": "2026-05-21T18:29:16.674Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

usn-8425-1

Vulnerability from osv_ubuntu

Published

2026-06-11 20:54

Modified

2026-06-17 22:06

Summary

libnginx-mod-js vulnerability

Details

It was discovered that njs did not properly handle certain client- controlled variables when processing ngx.fetch() requests. An attacker could possibly use this issue to trigger a heap buffer overflow, resulting in arbitrary code execution or a denial of service.

References

URL

Type

	https://ubuntu.com/security/notices/USN-8425-1	ADVISORY
	https://ubuntu.com/security/CVE-2026-8711	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-8711",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:26.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libnginx-mod-http-js",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "libnginx-mod-stream-js",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "njs",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "libnginx-mod-js",
        "purl": "pkg:deb/ubuntu/libnginx-mod-js@0.9.4-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.4-1ubuntu0.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.1-1ubuntu2",
        "0.9.1-1ubuntu3",
        "0.9.4-1~build1",
        "0.9.4-1",
        "0.9.4-1build1",
        "0.9.4-1build2"
      ]
    }
  ],
  "aliases": [],
  "details": "It was discovered that njs did not properly handle certain client-\ncontrolled variables when processing ngx.fetch() requests. An attacker\ncould possibly use this issue to trigger a heap buffer overflow, resulting\nin arbitrary code execution or a denial of service.",
  "id": "USN-8425-1",
  "modified": "2026-06-17T22:06:46Z",
  "published": "2026-06-11T20:54:04Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8425-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-8711"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "libnginx-mod-js vulnerability",
  "upstream": [
    "UBUNTU-CVE-2026-8711"
  ]
}

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.

Detection rules are retrieved from Rulezet.

Action not permitted

ubuntu-cve-2026-8711

Vulnerability from osv_ubuntu

CVE-2026-8711 (GCVE-0-2026-8711)

usn-8425-1

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature