Answer in brief
CVE-2026-53718 records a Medium severity vulnerability in Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass. The current sources do not mark it as known exploited. The current feed maps envoyproxy/gateway (generic), github.com/envoyproxy/gateway (go), github.com/envoyproxy/gateway (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps envoyproxy/gateway (generic), github.com/envoyproxy/gateway (go), github.com/envoyproxy/gateway (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| envoyproxy/gatewaygeneric | < 1.7.4 || >= 1.8.0-rc.0, < 1.8.1 | Not reported |
| github.com/envoyproxy/gatewaygo | >=1.8.0-rc.0,<1.8.1 | 1.8.1 |
| github.com/envoyproxy/gatewaygo | <1.7.4 | 1.7.4 |
Published upstream
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 16, 2026
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.
Quoted source text, attributed separately from HOL analysis.