CVE-2026-63379
mediumpriority · track · 0EPSS 0.007 · 53 %ileDEFREPSS · scored 2026-10-28
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.7–6.3
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (16)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3419Red Hat Enterprise Linux (corosync, libevent, libsoup): Mehrere SchwachstellenDeutsch2026-09-16csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen oder Denial-of-Service-Zustände herbeizuführen.
- CERTFR-2026-AVI-1336Multiples vulnérabilités dans les produits IBMFrançais2026-10-16vendor · certfrFR
- CERTFR-2026-AVI-1378Multiples vulnérabilités dans les produits IBMFrançais2026-10-23vendor · certfrFR
sources
Which sources assert this record, and when.
references (5) nvd
External citations — patches, advisories, analysis.
- https://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aefa1636
- https://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a4c485
- 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
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