Traefik: Gateway API TraefikService backend accepts rest@internal, allowing unauthorized exposure of the REST provider despite providers.rest.insecure=false

Summary

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.46, 3.6.17, and 3.7.1, Traefik's Kubernetes Gateway API provider allows a tenant with HTTPRoute creation permissions to expose the REST provider handler, bypassing the providers.rest.insecure=false setting. The Gateway provider accepts any TraefikService backend reference whose name ends with @internal, making it possible to route traffic to rest@internal in addition to the intended api@internal. In shared Gateway deployments where the REST provider is enabled, this allows a low-privileged actor to gain live dynamic configuration write access to Traefik, enabling unauthorized reconfiguration of routers and services. This vulnerability is fixed in 2.11.46, 3.6.17, and 3.7.1.

Timeline

1. May 15, 2026, 4:30 PM UTCCVE published
2. May 16, 2026, 1:12 AM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Aug 13, 2026, 12:04 PM UTCRecord last updated

Affected versions

• traefik traefik

  fixed in 2.11.46; From 3.0.0-beta1 · fixed in 3.6.17; From 3.7.0-rc.0 · fixed in 3.7.1

• github.com/traefik/traefik/v3Go

  From 3.7.0 · fixed in 3.7.1

• github.com/traefik/traefik/v3Go

  fixed in 3.6.17

• github.com/traefik/traefik/v2Go

  fixed in 2.11.46

• github.com/traefik/traefikGo

  through 1.7.34

• github.com/traefik/traefikGo

  All versions

• github.com/traefik/traefik/v3Go

  fixed in 3.6.17; From 3.7.0 · fixed in 3.7.1

References 4