Traefik: >> Traefik >> 3.7.3 Security Vulnerabilities
Traefik is an open source HTTP reverse proxy and load balancer. From v3.7.0 prior to v3.7.6, Traefik's Kubernetes Gateway API provider may resolve two accepted HTTPRoutes that target the same backend Service:port but configure different backendRef filters to the same child service and apply only one route's filter set to all requests reaching that backend. In Gateway deployments where backendRef filters set security-sensitive headers, such as tenant identity, authorization context, or values the backend trusts, an attacker who can create an accepted HTTPRoute sharing the same backend Service:port may cause their route's filter context to be applied to another route's requests, potentially crossing namespace boundaries when a ReferenceGrant permits cross-namespace targeting. This issue is fixed in version v3.7.6.
CVSS Score
6.3
EPSS Score
0.002
Published
2026-07-06
Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth, DigestAuth, and ForwardAuth middlewares strip canonical-cased spoofed identity headers before writing Traefik's own value, but do not account for underscore-variant header names, which many backends normalize identically to dashed forms. An attacker able to reach a protected route can inject an underscore-variant header that survives Traefik's stripping and reaches the backend alongside, or on the unauthenticated ForwardAuth authResponseHeaders path instead of, the value Traefik intended to set, spoofing identity or authorization context. This issue is fixed in versions v2.11.51, v3.6.22, and v3.7.6.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-07-06
Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's ForwardAuth middleware, even when configured with trustForwardHeader: false, derives the X-Forwarded-Port header sent to the authentication service from the original incoming request instead of the sanitized forwarded request. As a result, an unauthenticated remote attacker can inject an X-Forwarded-Proto: https header over a plain HTTP connection and cause Traefik to forward X-Forwarded-Port: 443 to the authentication service, bypassing port-based authorization checks. This issue is fixed in versions v2.11.51, v3.6.22, and v3.7.6.
CVSS Score
6.9
EPSS Score
0.002
Published
2026-07-06
Traefik is an HTTP reverse proxy and load balancer. Prior to 3.6.21 and 3.7.5, there is a high severity vulnerability in Traefik's Kubernetes Gateway provider affecting the crossProviderNamespaces allowlist. For HTTPRoute rules that declare multiple (WRR) backendRefs, Traefik evaluates the allowlist against the target backendRef.namespace instead of the route's own namespace. As a result, an HTTPRoute created in a namespace that is not allow-listed can reference a cross-provider TraefikService such as api@internal, dashboard@internal or rest@internal by pointing backendRef.namespace at an allow-listed namespace covered by a Gateway API ReferenceGrant, exposing internal Traefik services on the data plane. Exploitation requires the ability to create an accepted HTTPRoute and a matching ReferenceGrant from an allow-listed namespace; it does not require any change to Traefik static configuration, RBAC, or the deployment itself. This vulnerability is fixed in 3.6.21 and 3.7.5.
CVSS Score
6.0
EPSS Score
0.003
Published
2026-06-23
Traefik is an HTTP reverse proxy and load balancer. From 3.7.0-ea.1 until 3.7.5, there is a medium severity vulnerability in Traefik's Kubernetes Ingress NGINX provider that causes affected routes to fail open. When an Ingress explicitly enables BasicAuth or DigestAuth through the supported nginx.ingress.kubernetes.io/auth-type and auth-secret annotations, but the referenced auth Secret cannot be resolved or parsed, Traefik logs the resolution error, skips installing the authentication middleware, and still emits a router to the backend service. A route that operators intended to protect is therefore published to the data plane without its authentication control, allowing unauthenticated access to the backend. The trigger is an invalid or unresolved auth dependency — a missing, malformed, unreadable, or policy-denied Secret — rather than an intentionally unprotected route. This vulnerability is fixed in 3.7.5.
CVSS Score
5.9
EPSS Score
0.004
Published
2026-06-23