CVE-2026-63382: Red Hat Multiple HTTP Parser Bugs Enable Request Smuggling
This Red Hat advisory covers CVE-2026-63382 in Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 and Red Hat Enterprise Linux 9.
Key facts
- Vendor rating
- High, CVSS 7.7
- CISA KEV
- Not listed (catalogue checked )
- Affected
- < 2.1.13; < 2.2.2-alpha
- Fixed in
- 2.1.13, 2.2.2, libevent-0:2.1.13-1.el10_2 and 26 more below
- Source published
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
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.
Red Hat Enterprise Linux, OpenShift (RHCOS), RHIVOS, and community products (Fedora, Hummingbird) ship affected versions of libevent. Red Hat severity: Important — CVSS 7.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L).
Weakness: CWE-444. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Cert Manager support for Red Hat OpenShift release 1.20; Red Hat Hardened Images; Red Hat Update Infrastructure 5; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat OpenShift Container Platform 4.
Text from the source record.
- < 2.1.13
- < 2.2.2-alpha
Official advisory · high-confidence parse· fetched ·verify at source
How to fix CVE-2026-63382
Upgrade to a fixed release named by Red Hat:
- 2.1.13
- 2.2.2
- libevent-0:2.1.13-1.el10_2
- libevent-0:2.1.8-11.el8_10
- libevent-0:2.1.13-1.el9_8
- cert-manager/jetstack-cert-manager-rhel9:1790223279
- cert-manager/cert-manager-istio-csr-rhel9:1790223719
- cert-manager/cert-manager-operator-rhel9:1790272426
- cert-manager/jetstack-cert-manager-acmesolver-rhel9:1790589998
- cert-manager/jetstack-cert-manager-rhel9:1790589912
- cert-manager/cert-manager-istio-csr-rhel9:1790589914
- cert-manager/cert-manager-operator-rhel9:1790589855
- libevent-main-2.1.13-0.1.hum1
- rhui5/cds-kubernetes-rhel9:1790241897
- rhui5/cds-rhel9:1790241954
- rhui5/haproxy-rhel9:1790241900
- rhui5/installer-rhel9:1790241922
- rhui5/rhua-rhel9:1790242004
- RHSA-2026:67909
- RHSA-2026:67908
- RHSA-2026:67910
- RHSA-2026:72394
- RHSA-2026:72395
- RHSA-2026:72399
- RHSA-2026:72470
and 4 more in the Red Hat advisory.
Vendor guidance
- 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.
End-of-life dates for Red Hat Enterprise Linux
CVE-2026-63382 in other vendors' advisories
- Veeam: KB4825
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