{"id":"CVE-2026-121966","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-121966","summary":"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,…","details":"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.","published":"2026-11-04T16:17:50.107","modified":"2026-11-04T16:17:50.303","cvss":{"score":8.7,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://github.com/traefik/traefik/security/advisories/GHSA-hrpp-p4fc-wwf8"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/traefik-before-2.11.60-and-3.7.16-forwardauth-ntlm-negotiate-identity-leak"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-11-04T16:17:50.303"}}