{"id":"CVE-2026-63382","aliases":["GHSA-q39v-w2g7-gr8j"],"url":"https://o3.security/vulnerability/CVE-2026-63382","summary":"libevent evhttp: Multiple HTTP Parser Bugs Enable Request Smuggling","details":"Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, the libevent evhttp parser in http.c inconsistently handles duplicate Transfer-Encoding headers, comma-separated Transfer-Encoding values, and bare line feeds in chunked framing. evhttp_find_header can select only the first header, evhttp_check_transfer_encoding_ was absent so the previous whole-string comparison fails to recognize valid lists ending in chunked, and evhttp_handle_chunked_read uses EVBUFFER_EOL_CRLF rather than EVBUFFER_EOL_CRLF_STRICT, accepting bare LF chunk terminators. When libevent is deployed behind a proxy that frames the same request differently, an unauthenticated remote attacker can desynchronize request boundaries and smuggle a second request, potentially bypassing access controls or poisoning caches. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.","published":"2026-08-20T17:51:15.156Z","modified":"2026-08-22T03:58:08.829676834Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":{"url":"https://github.com/libevent/libevent/commit/10abb34b8dc3e1184de315dd261ce4b77563cda6","label":"libevent/libevent@10abb34"},"references":[{"type":"WEB","url":"https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"},{"type":"WEB","url":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63382.json"},{"type":"ADVISORY","url":"https://github.com/libevent/libevent/security/advisories/GHSA-q39v-w2g7-gr8j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63382"},{"type":"FIX","url":"https://github.com/libevent/libevent/commit/10abb34b8dc3e1184de315dd261ce4b77563cda6"},{"type":"FIX","url":"https://github.com/libevent/libevent/commit/5119ceb00557bf007f9065709e852686f3c0bb6e"},{"type":"FIX","url":"https://github.com/libevent/libevent/commit/83ba67373032334559b82409db035dd8c3cc1660"},{"type":"FIX","url":"https://github.com/libevent/libevent/commit/ac38703b2d312200c4f967f02936af0118d384a0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-22T03:58:08.829676834Z"}}