Paper/Archive/CVE-2026-85596

CVE-2026-85596

traefik traefik — Traefik v3.7 Authentication Bypass via TLS Option Conflict

Description · from the CVE record

Traefik versions >= v3.7.0 and <= v3.7.10 contain an authentication bypass in the Kubernetes Ingress NGINX provider. The TLS option generated for an Ingress carrying the nginx.ingress.kubernetes.io/auth-tls-secret annotation was named after the Ingress namespace and name. As a result, two Ingress objects sharing the same host, the same client CA secret, and the same client-authentication mode produced two distinct TLS option names for that host. Traefik treats this as a TLS options conflict and falls back to the entry point's default TLS configuration, which does not request a client certificate, so a route configured with nginx.ingress.kubernetes.io/auth-tls-verify-client: "on" becomes reachable without a client certificate. Only the v3.7 line is affected; the issue is fixed in v3.7.11.

Affected

ProductAffectedFixed inSource
traefik3.7.0 – 3.7.10–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
VulnCheck (CNA)8.2CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: partial

References

advisorygithub.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwqwriteupvulncheck.com/advisories/traefik-3.7-authentication-bypass-via-tls-option-conflict