Bug 2529028 (CVE-2026-85596)

Summary: CVE-2026-85596 github.com/traefik/traefik: Traefik: Authentication bypass due to TLS configuration conflict
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: anjoseph, jprabhak, sdawley, wtam
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Traefik. This vulnerability allows a remote attacker to bypass authentication, gaining unauthorized access to protected routes. This occurs due to a conflict in how Traefik handles Transport Layer Security (TLS) options when specific Kubernetes Ingress objects are configured. The conflict causes Traefik to use a less secure default configuration, negating the requirement for client certificates.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-05 10:41:14 UTC 
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.