Traefik HTTP/3 Backend NTLM Connection Reuse

{
  "id": "cf6fabe8cdeb9c32d78b366943b50f2e53eea6e25f95b6b075673b9ab842fd73",
  "url": "https://osv.dev/vulnerability/CVE-2026-88007",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Traefik HTTP/3 Backend NTLM Connection Reuse",
    "summary": "Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.0 until 2.11.57 and 3.7.13, the HTTP/3 entrypoint ConnContext does not call service.AddTransportOnContext, so kerberosRoundTripper uses a shared backend transport instead of a transport dedicated to each frontend connection. With HTTP/3 enabled, a backend using connection-bound NTLM or Negotiate authentication, and backend keep-alive, an unrelated client can reuse a backend connection authenticated for a victim, read victim-only data, and act as that victim without the victim credentials. This issue is fixed in 2.11.57 and 3.7.13.",
    "evidence": "osv:CVE-2026-88007",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-88007",
      "aliases": [
        "CVE-2026-88007",
        "GHSA-qqjf-53cj-pwvv",
        "GO-2026-6466"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/traefik/traefik",
              "type": "GIT",
              "events": [
                {
                  "introduced": "23c26d64eeb72eaecaecedc31ca740e83304fde2"
                },
                {
                  "fixed": "d87731461f0c7beb6fdbcc5a5655a44ce56e537a"
                },
                {
                  "introduced": "d99d2f95e66a28ee8180634dc80fdf13ba68c62a"
                },
                {
                  "fixed": "e8f398ee30ca5643158ea9094b701b8eae9849e5"
                },
                {
                  "fixed": "ff39c47d7459dec9cd8de63c1a4e7aa7315bdc1c"
                },
                {
                  "fixed": "839eb7f48a16849f22762b7e3bdfc58253146cd7"
                },
                {
                  "fixed": "fc92cc118a0557a029c7019d5ee06665127b0f13"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.8.2"
                      },
                      {
                        "fixed": "2.11.56"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.0.0"
                      },
                      {
                        "fixed": "3.7.12"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ff39c47d7459dec9cd8de63c1a4e7aa7315bdc1c"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "839eb7f48a16849f22762b7e3bdfc58253146cd7"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2.11.57"
                  },
                  {
                    "range": [
                      {
                        "fixed": "fc92cc118a0557a029c7019d5ee06665127b0f13"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.7.13"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-88007.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.987383309Z",
      "provider": "osv",
      "references": [
        "https://github.com/traefik/traefik/releases/tag/v2.11.57",
        "https://github.com/traefik/traefik/releases/tag/v3.7.13",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88007.json",
        "https://github.com/traefik/traefik/security/advisories/GHSA-qqjf-53cj-pwvv",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-88007",
        "https://github.com/traefik/traefik/commit/ff39c47d7459dec9cd8de63c1a4e7aa7315bdc1c",
        "https://github.com/traefik/traefik/pull/13812"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-287",
          "CWE-863"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88007.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-88007",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 494685,
  "published_at": "2026-09-10T14:47:28.27+00:00"
}