CVE-2026-63379
MEDIUM
6,3
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A
Description
AI Translation Available
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent processes chunked HTTP trailers in http.c through evhttp_read_trailer and merges them into request headers. The fix introduces evhttp_parse_headers_impl_ and a temporary trailer header list. An unauthenticated remote attacker can place security-sensitive fields in trailers so that an upstream proxy and the libevent application interpret different effective headers, enabling header smuggling, authorization bypass, proxy-header spoofing, or cache poisoning. The fix parses trailers into a temporary header list and discards them instead of merging them into req->input_headers. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
444
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
IncompleteCommon Consequences
Security Scopes Affected:
Integrity
Non-Repudiation
Access Control
Potential Impacts:
Unexpected State
Hide Activities
Bypass Protection Mechanism
Applicable Platforms
Technologies:
Web Based, Web Server
https://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aef…
https://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a…
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-2gmv-p5m7-98p6