CVE-2026-54765
HighCVSS 8.5Exploitation Probability (EPSS)
Low risk27th percentile - higher than 27% of all known CVEs
Summary
Traefik versions 3.7.0 through 3.7.5 have a vulnerability in the Kubernetes Gateway API provider where two accepted HTTPRoutes targeting the same backend Service:port but with different backendRef filters may apply only one route's filter set to all requests reaching that backend. An attacker can impose their filter context on another route's requests, potentially crossing namespace boundaries.
Risk Assessment
The risk is privilege escalation or tenant isolation breach when backendRef filters set security-sensitive headers like tenant identity or authorization context. An attacker can override these headers, leading to unauthorized access or impersonation.
Recommendation
Upgrade Traefik to version 3.7.6 or later immediately. If upgrade is not possible, temporarily avoid using backendRef filters in HTTPRoute or restrict route creation to trusted entities.
Original NVD description (English source)
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.