{"id":"CVE-2026-63385","title":"Libevent is an event notification library","summary":"Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause dow…","severity":"high","cwe":["CWE-444"],"published":"2026-08-20","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:19:49.197","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63385","references":[{"url":"https://github.com/libevent/libevent/commit/758be0c0f69c1934ef9a84ab39e9f9e5fde2e6d0","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/commit/9170dd35e64714613e8d13b290587cfc28e258e2","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63385.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-63385"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2520666"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63385"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63385"},{"url":"https://access.redhat.com/errata/RHSA-2026:67909"},{"url":"https://access.redhat.com/errata/RHSA-2026:67908"},{"url":"https://access.redhat.com/errata/RHSA-2026:67910"},{"url":"https://access.redhat.com/errata/RHSA-2026:63388"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00403,"epssPercentile":0.34307,"ingestedAt":"2026-09-09T21:22:45.545Z","vendor":"Red Hat","product":"Red Hat Enterprise Linux BaseOS (v. 8)","affected":["enterprise_linux 6","enterprise_linux 7","openshift_container_platform 4","enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_8","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_8","enterprise_linux_baseos_v_9","hardened_images"],"patched":["enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_8","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_8","enterprise_linux_baseos_v_9","hardened_images"],"cvss":7.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L","cvssSource":"vendor","slug":"CVE-2026-63385","body":"## Overview\n\nLibevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause downstream C string operations to truncate a path and bypass validation performed on a different representation. evhttp_header_is_valid_value also accepts obsolete line folding in header values containing carriage return or line feed characters, allowing a proxy and libevent to interpret headers differently and enabling header injection or access control bypass. The CRLF header acceptance is fixed in versions 2.1.13 and 2.2.2-alpha, but the reviewed patches do not clearly remediate the URI NUL-truncation condition.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:67909** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:67909)\n- **RHSA-2026:67908** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux BaseOS (v. 8) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:67908)\n- **RHSA-2026:67910** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:67910)\n- **RHSA-2026:63388** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63388)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63385.json)","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":42.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":206413,"id":"CVE-2026-63385","ts":1789663225615,"field":"cvss","old":null,"new":"7.7"},{"seq":206412,"id":"CVE-2026-63385","ts":1789663225615,"field":"severity","old":"none","new":"high"}]}