CVE-2026-53718

medium

Description

Envoy Gateway is an open source project for managing Envoy Proxy as a standalone or Kubernetes-based application gateway. Prior to 1.7.4 and 1.8.1, an HTTPRoute can use an extension-managed custom backendRef to reference a backend resource in another namespace without a matching Gateway API ReferenceGrant in the target namespace. The custom-backend branch in internal/gatewayapi/route.go omits validateBackendNamespace, allowing the route-owning namespace to bind to and use the resource without the backend namespace owner's consent and violating the Gateway API cross-namespace authorization model. This issue is fixed in versions 1.7.4 and 1.8.1.

References

https://github.com/envoyproxy/gateway/security/advisories/GHSA-fcrp-7gc2-93g7

https://github.com/envoyproxy/gateway/releases/tag/v1.8.1

https://github.com/envoyproxy/gateway/releases/tag/v1.7.4

https://github.com/envoyproxy/gateway/pull/9173

https://github.com/envoyproxy/gateway/pull/9172

https://github.com/envoyproxy/gateway/pull/9171

https://github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead

https://github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7

https://github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464

Details

Source: Mitre, NVD

Published: 2026-09-14

Updated: 2026-09-15

Risk Information

CVSS v2

Base Score: 6.1

Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:P/A:P

Severity: Medium

CVSS v3

Base Score: 6.4

Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L

Severity: Medium

EPSS

EPSS: 0.00043