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{"bugzilla": {"description": "libevent: Libevent: HTTP header smuggling allows authorization bypass or cache poisoning", "id": "2520667", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2520667"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-444", "details": ["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.", "A flaw was found in Libevent, an event notification library. An unauthenticated remote attacker can exploit a vulnerability where chunked HTTP (Hypertext Transfer Protocol) trailers are incorrectly merged into request headers. This allows the attacker to place security-sensitive fields in trailers, causing an upstream proxy and the Libevent application to interpret different effective headers. This can lead to header smuggling, authorization bypass, proxy-header spoofing, or cache poisoning."], "name": "CVE-2026-63379", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "libevent", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "libevent", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "libevent2", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "libevent", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "libevent", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "libevent", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "libevent", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-08-20T17:55:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-63379\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-63379\nhttps://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aefa1636\nhttps://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a4c485\nhttps://github.com/libevent/libevent/releases/tag/release-2.1.13-stable\nhttps://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha\nhttps://github.com/libevent/libevent/security/advisories/GHSA-2gmv-p5m7-98p6"], "threat_severity": "Moderate"}