Threats affecting pkg:golang/traefik

Traefik before 2.11.58 and 3.7.13 contains an authentication bypass vulnerability that allows unauthenticated clients to skip client-certificate checks because negated Host matchers are counted as served domains. Attackers can reach backends protected by RequireAndVerifyClientCert when a router rule with !Host() creates a TLS options conflict that falls back to the default options.

CVE-2026-114642 is a vulnerability in Traefik versions 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14. It involves improper certificate validation due to reuse of TLS client configurations across backend services. An unauthenticated client can exploit this to bypass TLS verification, including root CA checks and server name validation, potentially compromising secure connections between services.

Traefik 2.11.x before 2.11.58 and 3.x before 3.7.14 contains a race condition in NTLM and Kerberos (Negotiate) backend authentication, where the per-connection sticky round tripper slot is read and written without synchronization. Remote attackers can send concurrent HTTP/2 or HTTP/3 requests over one connection to orphan backend connections, break connection-bound authentication, or crash Traefik.

Traefik from v3.7.0 before v3.7.14 contains an authentication bypass vulnerability in its Kubernetes Ingress-NGINX provider that forwards client-supplied Ssl-Client-* headers on the plaintext HTTP router. When ssl-redirect is disabled alongside auth-tls-pass-certificate-to-upstream, unauthenticated attackers can send Ssl-Client-Verify: SUCCESS with a chosen certificate subject and issuer to impersonate mTLS identities.

Traefik 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14 contains an authentication bypass because a first request preauthenticated with an Authorization: Negotiate token authenticates a socket in the globally shared backend connection pool, which is never isolated. Unauthenticated attackers on separate frontend connections can be assigned that NTLM/Kerberos-bound socket and perform reads or writes with the victim's identity.

Traefik versions 3.7.0 through 3.7.13 have an improper authentication vulnerability in the Kubernetes Ingress NGINX provider. This flaw occurs due to merging client certificate authorities (CAs) when auth-tls-secret names collide after dot-to-dash normalization. As a result, attackers with certificates from a different host's CA can gain unauthorized access to hosts that require their own client CA, while legitimate clients of those hosts are denied access. The issue is fixed in version 3.7.14.

Traefik from v3.2.0 before v3.7.14 contains an authentication bypass vulnerability in the experimental FastProxy connection pool, which fails to pin NTLM/Negotiate-authenticated backend connections to their frontend connection. Unauthenticated clients can be handed a pooled keep-alive backend connection where a victim completed an NTLM or Negotiate handshake, letting them read victim data and act as that victim.

Traefik v3.7.13 before v3.7.14 contains an access-control bypass in the Kubernetes Ingress NGINX provider, where the HTTP router generated for ssl-passthrough Ingresses on non-TLS entry points never applies the Ingress's access-control annotations. Unauthenticated attackers reaching the HTTP entry point with the Ingress host can access backends protected by auth-type, auth-url, or whitelist-source-range annotations, with nothing logged.

Traefik before v2.11.58 and v3.7.14 contains an authentication bypass vulnerability in its SNI check, which is skipped when request TLS state is nil. Unauthenticated clients can send HTTP/2 requests with the :scheme http pseudo-header over TLS on Go 1.27 builds to reach routers requiring client certificates without presenting one.

Traefik before 2.11.46, 3.x before 3.6.17, and 3.7.0 lack namespace validation for Ingress and Service annotations in the Kubernetes Ingress provider, allowing references to Middlewares, ServersTransports, and TLSOptions in other namespaces. Attackers able to create or update Ingress or Service resources in one namespace can set router.middlewares or service.serverstransport annotations to obtain another tenant's injected credentials or reuse its client certificates, bypassing namespace-based tenant isolation.