envoyproxy/gateway · Security
Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass
- GHSA ID
- GHSA-fcrp-7gc2-93g7
- CVE ID
- CVE-2026-53718
- Severity
- medium
- Published
- Updated
- CVSS
- 6.4 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
- CVSS v3
- 6.4 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
Description
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
CWEs
- CWE-862 · Missing Authorization