undici vulnerable to Denial of Service via TLS 1.2 certificate-changing renegotiation

{
  "id": "b06d92df8ab28fa0f2aa94924b4122d2643f1319a081d6a81809d76078eef831",
  "url": "https://osv.dev/vulnerability/GHSA-qrxm-fqhp-jwvm",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "undici vulnerable to Denial of Service via TLS 1.2 certificate-changing renegotiation",
    "summary": "## Impact undici crashes the client process when a TLS 1.2 server renegotiates after the connection is established and presents a different, CA-trusted certificate whose hostname does not match the requested host. Node.js re-runs hostname verification on the renegotiated handshake and destroys the socket with `ERR_TLS_CERT_ALTNAME_INVALID`. undici's established socket error handler asserted that this error code could never occur, so the peer-controlled error became an uncaught `AssertionError` that terminates the Node.js process. Both the HTTP/1.1 and HTTP/2 paths are affected. A malicious or compromised HTTPS endpoint reached through undici or the global `fetch()` can crash the client with a single server-initiated renegotiation, taking down all in-flight requests and background work in the process. Only TLS 1.2 is affected, because TLS 1.3 does not support renegotiation. Exploitation does not require a CA compromise: the attacker controls the endpoint and can present two ordinary valid certificates, the first matching the requested URL and the second intentionally not matching it. ## Patches Upgrade to undici 6.29.1, 7.30.1, or 8.12.2. ## Workarounds Restrict outbound connections to TLS 1.3, for example by setting `connect: { minVersion: 'TLSv1.3', maxVersion: 'TLSv1.3' }` on the client or agent, so that renegotiation cannot occur, when the target endpoints support TLS 1.3.",
    "evidence": "osv:GHSA-qrxm-fqhp-jwvm",
    "products": [
      {
        "name": {
          "value": "undici",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.29.1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "undici",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.30.1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "undici",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "8.12.2",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-qrxm-fqhp-jwvm",
      "aliases": [
        "CVE-2026-87018",
        "GHSA-qrxm-fqhp-jwvm"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "4.2.1"
                },
                {
                  "fixed": "6.29.1"
                }
              ]
            }
          ],
          "package": {
            "name": "undici",
            "purl": "pkg:npm/undici",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-qrxm-fqhp-jwvm/GHSA-qrxm-fqhp-jwvm.json"
          }
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "7.0.0"
                },
                {
                  "fixed": "7.30.1"
                }
              ]
            }
          ],
          "package": {
            "name": "undici",
            "purl": "pkg:npm/undici",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-qrxm-fqhp-jwvm/GHSA-qrxm-fqhp-jwvm.json"
          }
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "8.0.0"
                },
                {
                  "fixed": "8.12.2"
                }
              ]
            }
          ],
          "package": {
            "name": "undici",
            "purl": "pkg:npm/undici",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-qrxm-fqhp-jwvm/GHSA-qrxm-fqhp-jwvm.json"
          }
        }
      ],
      "modified": "2026-10-27T19:15:22.403573595Z",
      "provider": "osv",
      "references": [
        "https://github.com/nodejs/undici/security/advisories/GHSA-qrxm-fqhp-jwvm",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-87018",
        "https://github.com/nodejs/undici/commit/12cfd96c3f430897656e3edc1c5e02be8c1cd309",
        "https://github.com/nodejs/undici/commit/b40fbfc0651703cf9fa9f6ced68b679f28d8bb28",
        "https://github.com/nodejs/undici/commit/e257e9f8fb42eedd50727b9cf65e548c8925e4a8",
        "https://cna.openjsf.org/security-advisories.html",
        "https://github.com/nodejs/undici",
        "https://github.com/nodejs/undici/releases/tag/v6.29.1",
        "https://github.com/nodejs/undici/releases/tag/v7.30.1",
        "https://github.com/nodejs/undici/releases/tag/v8.12.2"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-248",
          "CWE-617"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": "2026-10-15T19:17:46Z",
        "github_reviewed_at": "2026-10-27T19:02:21Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-87018",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 484991,
  "published_at": "2026-10-27T19:02:21+00:00"
}