{"id":"CVE-2026-48521","published":"2026-09-21T20:17:25.463","lastModified":"2026-09-21T20:17:25.463","description":"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.","cvssScore":5.9,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cwes":["CWE-476"],"vendors":[],"products":[],"references":[{"url":"https://github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1","tags":[]},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3","tags":[]},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3","tags":[]}],"exploitRefs":[{"url":"https://github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1","tags":[]},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3","tags":[]},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3","tags":[]}],"hasPoc":true,"ai":{"summary":"The flaw allows dereferencing of a null pointer in Envoy's connection pool allocation logic, potentially leading to worker crashes under specific conditions.","exploitability":"Exploitation requires HTTP/3 protocol usage and contexts without transport-socket options; relatively difficult due to specific preconditions.","blast_radius":"If exploited, it could cause service disruptions by crashing Envoy workers handling certain traffic patterns.","remediation":"Update to Envoy versions 1.36.10, 1.37.6, 1.38.4, or 1.39.1 to mitigate the issue.","tags":["memory-dereference","protocol-dependency","service-disruption"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-22T06:23:25.614Z"}}