HTTP Request Smuggling The advisory has been revoked - it doesn't affect any version of package libevent (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RHEL10-LIBEVENT-19506525
- published3 Sept 2026
- disclosed20 Aug 2026
Introduced: 20 Aug 2026
CVE-2026-63382 (opens in a new tab)Amendment
The Red Hat security team deemed this advisory irrelevant for RHEL:10.
NVD Description
Note: Versions mentioned in the description apply only to the upstream libevent package and not the libevent package as distributed by RHEL.
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.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2520660
- https://access.redhat.com/security/cve/CVE-2026-63382
- https://access.redhat.com/errata/RHSA-2026:63388
- https://access.redhat.com/errata/RHSA-2026:67909
- https://github.com/libevent/libevent/commit/10abb34b8dc3e1184de315dd261ce4b77563cda6
- https://github.com/libevent/libevent/commit/5119ceb00557bf007f9065709e852686f3c0bb6e
- https://github.com/libevent/libevent/commit/83ba67373032334559b82409db035dd8c3cc1660
- https://github.com/libevent/libevent/commit/ac38703b2d312200c4f967f02936af0118d384a0
- https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable
- https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha
- https://github.com/libevent/libevent/security/advisories/GHSA-q39v-w2g7-gr8j