{"apiVersion":"1.0","identifier":"CVE-2026-63379","description":"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.","publishedAt":"2026-08-20T18:16:35","lastModifiedAt":"2026-08-25T16:17:04","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63379","cvssScore":6.3,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","epssProbability":0.00518,"riskScore":0.66,"affectedProduct":"libevent","affectedVersions":"<2.1.13,<2.2.2-alpha","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-63379","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-63379","en":"https://www.redsauce.net/en/cves/CVE-2026-63379","fr":"https://www.redsauce.net/fr/cves/CVE-2026-63379","pt":"https://www.redsauce.net/pt/cves/CVE-2026-63379","de":"https://www.redsauce.net/de/cves/CVE-2026-63379","sk":"https://www.redsauce.net/sk/cves/CVE-2026-63379","el":"https://www.redsauce.net/el/cves/CVE-2026-63379"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-63379"}}