libnginx-mod-js — security advisory

{
  "id": "1a7e31bf0886fcc66951d39288b3b788f0e04b814f19dec78db8ca38c8b8e285",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-8711",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-8711",
    "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.",
    "evidence": "osv:UBUNTU-CVE-2026-8711",
    "products": [
      {
        "name": {
          "value": "libnginx-mod-js",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "0.9.4-1build2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.9.9-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.0.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.0.0-3",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "libnginx-mod-js",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.9.4-1ubuntu0.1~esm1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "0.9.1-1ubuntu2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "0.9.1-1ubuntu3",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "0.9.4-1~build1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "0.9.4-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "0.9.4-1build1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "0.9.4-1build2",
            "evidence": "/affected/1/versions"
          }
        ]
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "UBUNTU-CVE-2026-8711",
      "aliases": [
        "UBUNTU-CVE-2026-8711"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "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_V4",
          "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": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "libnginx-mod-js",
            "purl": "pkg:deb/ubuntu/libnginx-mod-js?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "0.9.4-1build2",
            "0.9.9-2",
            "1.0.0-1",
            "1.0.0-3"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-8711.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libnginx-mod-http-js",
                "binary_version": "1.0.0-3"
              },
              {
                "binary_name": "libnginx-mod-stream-js",
                "binary_version": "1.0.0-3"
              },
              {
                "binary_name": "njs",
                "binary_version": "1.0.0-3"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0.9.4-1ubuntu0.1~esm1"
                }
              ]
            }
          ],
          "package": {
            "name": "libnginx-mod-js",
            "purl": "pkg:deb/ubuntu/libnginx-mod-js?arch=source&distro=esm-apps%2Fresolute",
            "ecosystem": "Ubuntu:Pro:26.04:LTS"
          },
          "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"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-8711.json"
          },
          "ecosystem_specific": {
            "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"
              }
            ],
            "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
          }
        }
      ],
      "modified": "2026-10-17T13:01:14.273355881Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-8711"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-8711",
        "https://www.cve.org/CVERecord?id=CVE-2026-8711",
        "https://my.f5.com/manage/s/article/K000161307",
        "https://ubuntu.com/security/notices/USN-8425-1"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-8711",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/1/score"
  },
  "source_id": "core-osv",
  "document_id": 361344,
  "published_at": "2026-05-19T15:16:00+00:00"
}