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.
Fix
Patch, vendor advisory and mitigation references on NVD 1
- https://github.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwq Exploit, Mitigation, Patch, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 8.2 · traefikNVD modified 2026-10-08 16:17
Affected (CPE criteria) 1
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*
References 2
- https://github.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwq Exploit, Mitigation, Patch, Vendor Advisory
- https://www.vulncheck.com/advisories/traefik-3.7-authentication-bypass-via-tls-option-conflict Third Party Advisory