{"id":"BIT-envoy-2026-26311","summary":"Envoy HTTP: filter chain execution on reset streams causing UAF crash","details":"Envoy is a high-performance edge/middle/service proxy. Prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13, a logic vulnerability in Envoy's HTTP connection manager (FilterManager) that allows for Zombie Stream Filter Execution. This issue creates a \"Use-After-Free\" (UAF) or state-corruption window where filter callbacks are invoked on an HTTP stream that has already been logically reset and cleaned up. The vulnerability resides in source/common/http/filter_manager.cc within the FilterManager::decodeData method. The ActiveStream object remains valid in memory during the deferred deletion window. If a DATA frame arrives on this stream immediately after the reset (e.g., in the same packet processing cycle), the HTTP/2 codec invokes ActiveStream::decodeData, which cascades to FilterManager::decodeData. FilterManager::decodeData fails to check the saw_downstream_reset_ flag. It iterates over the decoder_filters_ list and invokes decodeData() on filters that have already received onDestroy(). This vulnerability is fixed in 1.37.1, 1.36.5, 1.35.8, and 1.34.13.","aliases":["CVE-2026-26311","GHSA-84xm-r438-86px"],"modified":"2026-09-08T08:47:31.552969409Z","published":"2026-03-12T08:39:46.109Z","database_specific":{"cpes":["cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:go:*:*"],"severity":"Medium"},"references":[{"type":"ADVISORY","url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-84xm-r438-86px"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-26311"}],"affected":[{"package":{"name":"envoy","ecosystem":"Bitnami","purl":"pkg:bitnami/envoy"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.34.13"},{"introduced":"1.35.0"},{"fixed":"1.35.9"},{"introduced":"1.36.0"},{"fixed":"1.36.5"},{"introduced":"1.37.0"},{"fixed":"1.37.1"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/envoy/BIT-envoy-2026-26311.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"}