CVE-2026-48521

{"id": "CVE-2026-48521", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-48521", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-21T20:02:39.214503Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 2.2}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "envoyproxy", "product": "envoy", "versions": [{"status": "affected", "version": "< 1.36.10"}, {"status": "affected", "version": ">= 1.37.0, < 1.37.6"}, {"status": "affected", "version": ">= 1.38.0, < 1.38.4"}, {"status": "affected", "version": ">= 1.39.0, < 1.39.1"}]}]}], "published": "2026-09-21T20:17:25.463", "references": [{"url": "https://github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/releases/tag/v1.36.10", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/releases/tag/v1.37.6", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/releases/tag/v1.38.4", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/releases/tag/v1.39.1", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1."}], "lastModified": "2026-10-05T14:09:45.933", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6A420B14-9ADA-4F6B-ACAA-3045E8690F04", "versionEndExcluding": "1.36.10"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1AD376F3-22D7-4BFB-B00C-BD68F464436F", "versionEndExcluding": "1.37.6", "versionStartIncluding": "1.37.0"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "840E030F-8746-4DBD-87C0-5DF7896294CC", "versionEndExcluding": "1.38.4", "versionStartIncluding": "1.38.0"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B5C1C594-8142-4F51-BE50-1AF50FD07129", "versionEndExcluding": "1.39.1", "versionStartIncluding": "1.39.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}