High [CVE-2026-54765] Unauthorized filter context application in Kubernetes Gateway API provider

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. The system may incorrectly apply the attacker's route filter context to another route's requests, potentially allowing unauthorized access or information disclosure across different namespaces.

This could lead to the application of security-sensitive headers from the attacker's route to legitimate requests, bypassing intended security controls. This Moderate flaw in Traefik's Kubernetes Gateway API provider, as deployed in Red Hat OpenShift Dev Spaces, could allow an attacker to apply their route's filter context to other requests.