GHSA-fcrp-7gc2-93g7: Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass
Impact
Envoy Gateway accepts extension-managed custom backendRefs from an HTTPRoute to a backend resource in another namespace without requiring a matching Gateway API ReferenceGrant in the target namespace. This breaks the Gateway API cross-namespace consent model: the namespace that owns the referenced backend resource does not need to opt in with a ReferenceGrant before another namespace’s HTTPRoute can use that resource.
Patches
1.7.4
1.8.1
Details
Original advisory: https://github.com/advisories/GHSA-fcrp-7gc2-93g7
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-53718 | coverage & exploitation status | NVD · CVE.org |
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