{"id":"CVE-2026-121966","aliases":[],"cve":{"records":[{"id":"CVE-2026-121966","source":"VulnCheck","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-11-04T12:48:39.813Z","published":"2026-11-04T15:33:28.106Z","modified":"2026-11-04T18:17:29.572Z"}],"publishers":[{"name":"VulnCheck","role":"CNA","organizationId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","modified":"2026-11-04T15:33:28.106Z"},{"name":"CISA-ADP","role":"ADP","organizationId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","modified":"2026-11-04T18:17:29.572Z"}],"references":[{"url":"https://github.com/traefik/traefik/security/advisories/GHSA-hrpp-p4fc-wwf8","tags":["vendor-advisory"],"source":"VulnCheck"},{"url":"https://www.vulncheck.com/advisories/traefik-before-2.11.60-and-3.7.16-forwardauth-ntlm-negotiate-identity-leak","tags":["third-party-advisory"],"source":"VulnCheck"}],"weaknesses":[{"id":"CWE-488","description":"Exposure of Data Element to Wrong Session","source":"VulnCheck"}],"applicability":[{"source":"VulnCheck","statements":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*","versionEndExcluding":"2.11.60"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0.0","versionEndExcluding":"3.7.16"}]}]}]}],"prioritization":[{"source":"CISA-ADP","type":"SSVC","role":"CISA Coordinator","timestamp":"2026-11-04T18:13:59.569753Z","decisions":[{"name":"Exploitation","value":"none"},{"name":"Automatable","value":"no"},{"name":"Technical Impact","value":"total"}]}]},"title":"Traefik before 2.11.60 and 3.7.16 ForwardAuth NTLM/Negotiate Identity Leak","titleSource":"VulnCheck","descriptionSource":"VulnCheck","description":"Traefik 2.x before 2.11.60 and 3.x before 3.7.16 sends ForwardAuth subrequests (and, in 3.7, Ingress NGINX auth-url requests) through an auth-server connection pool shared by all clients, exposing connection-bound NTLM or Negotiate authentication. An unauthenticated attacker can reuse another user's authenticated connection, receiving the victim's identity via authResponseHeaders to access backends as that user.","score":8.7,"severity":"high","published":"2026-11-04T15:33:28.106Z","modified":"2026-11-04T18:17:29.572Z","withdrawn":false,"knownExploited":false,"affected":[],"products":[{"vendor":"traefik","name":"traefik","platforms":[],"versions":[{"version":"0","status":"affected","lessThan":"2.11.60","versionType":"semver"},{"version":"2.11.60","status":"unaffected","versionType":"semver"}],"defaultStatus":"unaffected","packageURL":"pkg:golang/github.com/traefik/traefik/v2","packageIdentity":{"ecosystem":"Go","name":"github.com/traefik/traefik/v2"},"cpes":[],"source":"VulnCheck","url":"https://www.cve.org/CVERecord?id=CVE-2026-121966"},{"vendor":"traefik","name":"traefik","platforms":[],"versions":[{"version":"3.0.0","status":"affected","lessThan":"3.7.16","versionType":"semver"},{"version":"3.7.16","status":"unaffected","versionType":"semver"}],"defaultStatus":"unaffected","packageURL":"pkg:golang/github.com/traefik/traefik/v3","packageIdentity":{"ecosystem":"Go","name":"github.com/traefik/traefik/v3"},"cpes":[],"source":"VulnCheck","url":"https://www.cve.org/CVERecord?id=CVE-2026-121966"}],"remediation":[],"references":["https://github.com/traefik/traefik/security/advisories/GHSA-hrpp-p4fc-wwf8","https://www.vulncheck.com/advisories/traefik-before-2.11.60-and-3.7.16-forwardauth-ntlm-negotiate-identity-leak"],"sources":[{"name":"CVE","id":"CVE-2026-121966","modified":"2026-11-04T18:17:29.572Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-121966"}],"assessments":[{"source":"VulnCheck","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","score":7},{"source":"VulnCheck","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","score":8.7}],"sourceAffected":[],"observedAt":"2026-11-04T18:34:58.975Z","kev":{"status":"not-listed","checkedAt":"2026-11-15T03:00:33.317Z"},"coverage":[{"source":"NVD","status":"no-result","checkedAt":"2026-11-04T16:05:32.986Z","attemptedAt":"2026-11-04T16:05:32.986Z"},{"source":"GHSA","status":"no-result","checkedAt":"2026-11-04T16:05:32.422Z","attemptedAt":"2026-11-04T16:05:32.422Z"},{"source":"EUVD","status":"no-result","checkedAt":"2026-11-04T16:05:32.466Z","attemptedAt":"2026-11-04T16:05:32.466Z"},{"source":"EPSS","status":"no-result","checkedAt":"2026-11-04T16:05:32.779Z","attemptedAt":"2026-11-04T16:05:32.779Z"}],"evidence":[],"aiSummary":{"text":"Traefik versions before 2.11.60 and 3.7.16 have an identity leak vulnerability, allowing an unauthenticated attacker to reuse another user's authenticated connection. The vulnerability exposes connection-bound NTLM or Negotiate authentication. An attacker can access backends as the victim user.","model":"@cf/meta/llama-3.3-70b-instruct-fp8-fast","generatedAt":"2026-11-04T16:01:08.456Z","sources":[{"name":"CVE","url":"https://www.cve.org/CVERecord?id=CVE-2026-121966"}]}}