{"id":"CVE-2026-53718","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-53718","generatedAt":"2026-10-28T05:28:00.262Z","title":"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…","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.","published":"2026-09-14T21:17:13.000Z","lastModified":"2026-09-25T14:10:14.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L"},"cwe":["CWE-862"],"affected":[],"epss":{"score":0.00413,"percentile":0.35386,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.41%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464","source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7","source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead","source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/gateway/pull/9171","source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/gateway/pull/9172","source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/gateway/pull/9173","source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/gateway/releases/tag/v1.7.4","source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/gateway/releases/tag/v1.8.1","source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/gateway/security/advisories/GHSA-fcrp-7gc2-93g7","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-53718","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}