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## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-qq9q-x9w4-chhj.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 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 holding a ReferenceGrant for a cross-namespace Service could therefore bind a Traefik Middleware from the backend namespace without a separate grant for that middleware, potentially injecting trusted reverse-proxy identity headers into downstream requests. The issue is fixed in version 3.7.7.

Source published

22 Jul 2026 12:32:18 UTC

Source modified

5 Aug 2026 22:01:01 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

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CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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