Executive brief
Envoy Gateway, a tool used to manage network traffic for applications, contains a security flaw in how it handles cross-namespace traffic. An attacker with limited access could bypass security boundaries to connect to backend resources in different administrative areas without the required permission from the resource owner. This could lead to unauthorized access to sensitive internal services or data.
Technical details
Envoy Gateway is vulnerable to a missing authorization check (CWE-862) when processing extension-managed custom backendRefs in HTTPRoutes. The software fails to verify the existence of a Gateway API ReferenceGrant in the target namespace, which is required to authorize cross-namespace references. An attacker with the ability to create HTTPRoutes in one namespace can reference and potentially interact with backend resources in another namespace without the owner's consent. This bypasses the standard Gateway API security model for cross-namespace resource sharing. The issue is fixed in versions 1.7.4 and 1.8.1.
Affected products
- Envoy Proxy Gateway < 1.7.4, >= 1.8.0-rc.0, < 1.8.1
Timeline
- 2026-06-05: disclosed
- 2026-07-16: advisory: GitHub Advisory published