Traefik Gateway API provider: colliding route identities let one namespace overwrite another's backend

Impact

Traefik builds router and service identities for Gateway API routes by hyphen-concatenating namespace, route name, gateway identity, entry point and rule index. Because the separator can appear inside the parts, two routes in different namespaces can produce the same identity, and the later one silently replaces the earlier one's backend. A tenant who can create a route in their own namespace can therefore capture traffic destined for another tenant's service, or point another namespace's hostname at a backend they control. On a shared GPU cluster where Traefik fronts per-tenant inference endpoints, that is cross-tenant traffic interception and request forgery with no control-plane privilege beyond the ability to create a route object in one namespace. Affects 3.0.0 up to 3.6.25 and 3.7.10.

Who can reach it

Any authenticated Kubernetes principal that can create Gateway API route objects (HTTPRoute, GRPCRoute, TCPRoute or TLSRoute) in a namespace attached to a shared Gateway. No cluster-admin rights are needed, and the attacker needs no access to the victim namespace.

What to do

Upgrade Traefik to 3.6.25 or 3.7.10 and roll the ingress deployment; a rolling restart of the Traefik pods is enough and no node work is involved. Until then, audit existing route names for the collision pattern and restrict who can attach routes to shared Gateways with ReferenceGrant and namespace selectors on the listener.

References

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