CVE-2026-63382
libevent evhttp: Multiple HTTP Parser Bugs Enable Request Smuggling
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.
| CWE | CWE-444 |
| Vendor | libevent |
| Product | libevent |
| Published | Aug 20, 2026 |
| Last Updated | Aug 20, 2026 |
Get instant alerts for libevent libevent
Be the first to know when new unknown vulnerabilities affecting libevent libevent are published — delivered to Slack, Telegram or Discord.