{"id":"BIT-envoy-2026-48521","summary":"Envoy: HTTP/3 connection pool selection null-derefs in ProdClusterManagerFactory::allocateConnPool when transport_socket_options is null","details":"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.","aliases":["CVE-2026-48521","GHSA-5vff-j9p4-38j3"],"modified":"2026-09-29T10:10:59.181206773Z","published":"2026-09-29T08:42:58.854Z","database_specific":{"cpes":["cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*"],"severity":"Medium"},"references":[{"type":"WEB","url":"https://github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48521"}],"affected":[{"package":{"name":"envoy","ecosystem":"Bitnami","purl":"pkg:bitnami/envoy"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.36.10"},{"introduced":"1.37.0"},{"fixed":"1.37.6"},{"introduced":"1.38.0"},{"fixed":"1.38.4"},{"introduced":"1.39.0"},{"fixed":"1.39.1"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/envoy/BIT-envoy-2026-48521.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}],"schema_version":"1.9.0"}