CVE-2026-121966
Dashboard / Vulnerabilities / CVE-2026-121966
Summary: Traefik before 2.11.60 and 3.7.16 ForwardAuth NTLM/Negotiate Identity Leak
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.
References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121966.json, https://github.com/traefik/traefik/security/advisories/GHSA-hrpp-p4fc-wwf8, https://nvd.nist.gov/vuln/detail/CVE-2026-121966, https://www.vulncheck.com/advisories/traefik-before-2.11.60-and-3.7.16-forwardauth-ntlm-negotiate-identity-leak
Affected packages
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