CVE-2026-53718

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-53718", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-10T16:43:31.241Z", "datePublished": "2026-09-14T20:12:12.224Z", "dateUpdated": "2026-09-15T13:55:25.432Z"}, "containers": {"cna": {"title": "Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass", "problemTypes": [{"descriptions": [{"cweId": "CWE-862", "lang": "en", "description": "CWE-862: Missing Authorization", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 6.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L", "version": "3.1"}}], "references": [{"name": "https://github.com/envoyproxy/gateway/security/advisories/GHSA-fcrp-7gc2-93g7", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/envoyproxy/gateway/security/advisories/GHSA-fcrp-7gc2-93g7"}, {"name": "https://github.com/envoyproxy/gateway/pull/9171", "tags": ["x_refsource_MISC"], "url": "https://github.com/envoyproxy/gateway/pull/9171"}, {"name": "https://github.com/envoyproxy/gateway/pull/9172", "tags": ["x_refsource_MISC"], "url": "https://github.com/envoyproxy/gateway/pull/9172"}, {"name": "https://github.com/envoyproxy/gateway/pull/9173", "tags": ["x_refsource_MISC"], "url": "https://github.com/envoyproxy/gateway/pull/9173"}, {"name": "https://github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464", "tags": ["x_refsource_MISC"], "url": "https://github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464"}, {"name": "https://github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7", "tags": ["x_refsource_MISC"], "url": "https://github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7"}, {"name": "https://github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead", "tags": ["x_refsource_MISC"], "url": "https://github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead"}, {"name": "https://github.com/envoyproxy/gateway/releases/tag/v1.7.4", "tags": ["x_refsource_MISC"], "url": "https://github.com/envoyproxy/gateway/releases/tag/v1.7.4"}, {"name": "https://github.com/envoyproxy/gateway/releases/tag/v1.8.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/envoyproxy/gateway/releases/tag/v1.8.1"}], "affected": [{"vendor": "envoyproxy", "product": "gateway", "versions": [{"version": "< 1.7.4", "status": "affected"}, {"version": ">= 1.8.0-rc.0, < 1.8.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-14T20:12:12.224Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-fcrp-7gc2-93g7", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-15T13:25:21.526527Z", "id": "CVE-2026-53718", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-15T13:55:25.432Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-53718", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-15T13:25:21.526527Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-15T13:25:23.152Z"}}], "cna": {"title": "Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass", "source": {"advisory": "GHSA-fcrp-7gc2-93g7", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.4, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "LOW", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}}], "affected": [{"vendor": "envoyproxy", "product": "gateway", "versions": [{"status": "affected", "version": "< 1.7.4"}, {"status": "affected", "version": ">= 1.8.0-rc.0, < 1.8.1"}]}], "references": [{"url": "https://github.com/envoyproxy/gateway/security/advisories/GHSA-fcrp-7gc2-93g7", "name": "https://github.com/envoyproxy/gateway/security/advisories/GHSA-fcrp-7gc2-93g7", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/envoyproxy/gateway/pull/9171", "name": "https://github.com/envoyproxy/gateway/pull/9171", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/envoyproxy/gateway/pull/9172", "name": "https://github.com/envoyproxy/gateway/pull/9172", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/envoyproxy/gateway/pull/9173", "name": "https://github.com/envoyproxy/gateway/pull/9173", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464", "name": "https://github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7", "name": "https://github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead", "name": "https://github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/envoyproxy/gateway/releases/tag/v1.7.4", "name": "https://github.com/envoyproxy/gateway/releases/tag/v1.7.4", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/envoyproxy/gateway/releases/tag/v1.8.1", "name": "https://github.com/envoyproxy/gateway/releases/tag/v1.8.1", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "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."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-862", "description": "CWE-862: Missing Authorization"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-14T20:12:12.224Z"}}}, "cveMetadata": {"cveId": "CVE-2026-53718", "state": "PUBLISHED", "dateUpdated": "2026-09-15T13:55:25.432Z", "dateReserved": "2026-06-10T16:43:31.241Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-09-14T20:12:12.224Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "gateway", "vendor": "envoyproxy", "versions": [{"status": "affected", "version": "< 1.7.4"}, {"status": "affected", "version": ">= 1.8.0-rc.0, < 1.8.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-53718", "lastModified": "2026-09-25T14:10:13.927", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 6.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 4.7, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-53718", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-09-15T13:25:21.526527Z", "version": "2.0.3"}}]}, "published": "2026-09-14T21:17:13.140", "references": [{"source": "security-advisories@github.com", "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"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-862"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.7.4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.8.0-rc.0,1.8.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "gateway", "source": "cna", "vendor": "envoyproxy"}, "product": "gateway", "vendor": "envoyproxy"}], "created": "2026-09-15T00:00:08.768459+00:00", "updated": "2026-09-20T22:15:05.375079+00:00", "vendors": ["envoyproxy", "envoyproxy$PRODUCT$gateway"]}