---
id: CVE-2026-53718
title: >-
  Envoy Gateway is an open source project for managing Envoy Proxy as a
  standalone or Kubernetes-based application gateway
summary: >-
  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 resour…
severity: medium
cvss: 6.4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L'
cwe:
  - CWE-862
vendor: envoyproxy
product: gateway
affected:
  - gateway < 1.7.4
  - 'gateway >= 1.8.0-rc.0, < 1.8.1'
patched:
  - github.com/envoyproxy/gateway 1.8.1
  - github.com/envoyproxy/gateway 1.7.4
published: '2026-09-14'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T14:10:13.927'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53718'
references:
  - url: >-
      https://github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464
    label: security-advisories@github.com
  - url: >-
      https://github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7
    label: security-advisories@github.com
  - url: >-
      https://github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead
    label: security-advisories@github.com
  - url: 'https://github.com/envoyproxy/gateway/pull/9171'
    label: security-advisories@github.com
  - url: 'https://github.com/envoyproxy/gateway/pull/9172'
    label: security-advisories@github.com
  - url: 'https://github.com/envoyproxy/gateway/pull/9173'
    label: security-advisories@github.com
  - url: 'https://github.com/envoyproxy/gateway/releases/tag/v1.7.4'
    label: security-advisories@github.com
  - url: 'https://github.com/envoyproxy/gateway/releases/tag/v1.8.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/envoyproxy/gateway/security/advisories/GHSA-fcrp-7gc2-93g7
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-fcrp-7gc2-93g7'
  - url: 'https://github.com/envoyproxy/gateway'
tags:
  - nvd
  - cve.org
  - ghsa
  - go
  - osv
epss: 0.00413
epssPercentile: 0.3288
aliases:
  - GHSA-fcrp-7gc2-93g7
  - BIT-envoy-gateway-2026-53718
  - GO-2026-6007
ecosystem: go
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T13:25:21.526527Z'
ingestedAt: '2026-07-16T19:57:16.781Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-53718)

Affected packages:

- `github.com/envoyproxy/gateway >= 1.8.0-rc.0, < 1.8.1`
- `github.com/envoyproxy/gateway < 1.7.4`

Patched in:

- `github.com/envoyproxy/gateway 1.8.1`
- `github.com/envoyproxy/gateway 1.7.4`

Source: https://github.com/advisories/GHSA-fcrp-7gc2-93g7