Traefik Gateway API HTTPRoute BackendRef ExtensionRef Namespace Confusion

Summary There is a medium-severity namespace-confusion vulnerability in Traefik's Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules.backendRefs.filters.extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route author...

Duplicate Advisory: Traefik Gateway API HTTPRoute BackendRef ExtensionRef Namespace Confusion

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-qq9q-x9w4-chhj. This link is maintained to preserve external references. Original Description Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API...

CVE-2026-65601 Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef

Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules.backendRefs.filters.extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route auth...

CVE-2026-65601

Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules.backendRefs.filters.extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route auth...

PT-2026-63359

Name of the Vulnerable Software and Affected Versions Traefik versions 3.7.0 through 3.7.6 Description A namespace confusion issue exists in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules.backendRefs.filters.extensionRef, the system incorrectly uses the backend Service...

Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass

Impact Envoy Gateway accepts extension-managed custom backendRefs from an HTTPRoute to a backend resource in another namespace without requiring a matching Gateway API ReferenceGrant in the target namespace. This breaks the Gateway API cross-namespace consent model: the namespace that owns the...

PT-2026-60690

Name of the Vulnerable Software and Affected Versions Envoy Gateway versions prior to 1.7.4 Envoy Gateway versions prior to 1.8.1 Description Envoy Gateway allows extension-managed custom backendRefs from an HTTPRoute to a backend resource in a different namespace without requiring a correspondin...

EUVD-2026-44773

Cilium is a networking, observability, and security solution. Prior to 1.17.17, 1.18.11, and 1.19.5, Cilium clusters using Gateway API allow users with permissions to create or update namespaced HTTPRoutes to mirror HTTP traffic to any Service in any namespace, bypassing the ReferenceGrant...

CVE-2026-56742

Cilium Gateway API vulnerability (CVE-2026-56742): Prior to versions 1.17.17, 1.18.11, and 1.19.5, clusters using Gateway API allowed users with write permissions on namespaced HTTPRoutes to mirror traffic to any Service in any namespace, bypassing ReferenceGrant checks. Impacted when Gateway API...

PT-2026-60281

Name of the Vulnerable Software and Affected Versions Cilium versions prior to 1.17.17 Cilium versions prior to 1.18.11 Cilium versions prior to 1.19.5 Description In clusters using the Gateway API, users with permissions to create or update namespaced HTTPRoutes can mirror HTTP traffic to any...

CVE-2026-54765 Traefik: Gateway HTTPRoute backendRef filters can leak backend context across routes sharing a Service:port

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...

CVE-2026-54761

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 allowlis...

EUVD-2026-38577

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 allowlis...

CVE-2026-54761 Traefik: Kubernetes Gateway crossProviderNamespaces bypass allows HTTPRoute outside the allowlist to expose internal Traefik services

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 allowlis...

CVE-2026-54761

Traefik vulnerability CVE-2026-54761 affects the Kubernetes Gateway provider: prior to 3.6.21 and 3.7.5, the crossProviderNamespaces allowlist is checked against backendRef.namespace instead of the HTTPRoute’s own namespace, enabling an attacker in a non-allowlisted namespace to reference interna...

Exploit for CVE-2026-54761

CVE-2026-54761: Traefik Kubernetes Gateway crossProviderNamesp...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization in the evaluation of the crossProviderNamespaces allowlist within the Kubernetes Gateway provider. An attacker can gain unauthorized access to internal services by creating an HTTPRoute in a non-allow-listed...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization in the evaluation of the crossProviderNamespaces allowlist within the Kubernetes Gateway provider. An attacker can gain unauthorized access to internal services by creating an HTTPRoute in a non-allow-listed...

Traefik: Kubernetes Gateway crossProviderNamespaces bypass allows HTTPRoute outside the allowlist to expose internal Traefik services

Summary 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...

PT-2026-50495

Name of the Vulnerable Software and Affected Versions Traefik versions prior to 3.6.21 Traefik versions prior to 3.7.5 Description An issue exists in the Kubernetes Gateway provider regarding the crossProviderNamespaces allowlist. When HTTPRoute rules declare multiple backendRefs Weighted Round...