CVE-2026-63382
libevent: libevent: Multiple HTTP Parser Bugs Enable Request Smuggling
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · August 21, 2026
Updated · November 2, 2026
Description
A flaw was found in libevent. The evhttp parser in libevent's http.c component inconsistently handles HTTP Transfer-Encoding headers and chunked framing. This inconsistency allows an unauthenticated remote attacker to desynchronize request boundaries when libevent is used behind a proxy. Successful exploitation could lead to request smuggling, potentially bypassing access controls or poisoning caches.
Statement
Red Hat Enterprise Linux, OpenShift (RHCOS), RHIVOS, and community products (Fedora, Hummingbird) ship affected versions of libevent.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 7.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
CWE-444 · Inconsistent Interpretation of HTTP Requests