{"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"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53718.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-53718"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2533373"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53718"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53718"}],"tags":["nvd","cve.org","ghsa","go","osv","csaf","vex","red-hat"],"epss":0.00413,"epssPercentile":0.35386,"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","slug":"CVE-2026-53718","body":"## Overview\n\nEnvoy 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-53718)\n\nAffected packages:\n\n- `github.com/envoyproxy/gateway >= 1.8.0-rc.0, < 1.8.1`\n- `github.com/envoyproxy/gateway < 1.7.4`\n\nPatched in:\n\n- `github.com/envoyproxy/gateway 1.8.1`\n- `github.com/envoyproxy/gateway 1.7.4`\n\nSource: https://github.com/advisories/GHSA-fcrp-7gc2-93g7\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Connectivity Link 1 · no fix planned: Red Hat Connectivity Link 1 · updated 2026-09-30 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53718.json)","depth":"sunlit","depthScore":35,"depthScoreParts":{"impact":35.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}