{"id":"CVE-2026-114437","title":"Chi Client IP Spoofing in ClientIPFromXFF via X-Forwarded-For","summary":"In the Golang Chi web framework, the ClientIPFromXFF middleware skips any X-Forwarded-For entry in a configured trusted CIDR but never verifies that the direct TCP peer in http.Request.RemoteAddr belongs to that CIDR. A client that can r…","severity":"medium","cvss":4.8,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","cvssSource":"cna","cwe":["CWE-348"],"vendor":"go-chi","product":"github.com/go-chi/chi/v5","affected":["github.com/go-chi/chi/v5 < 5.4.0"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-21T15:16:38.882767Z"},"exploitAvailable":true,"published":"2026-10-21","updated":"2026-10-21","sourceUpdated":"2026-10-21T17:19:13.809Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-114437","references":[{"url":"https://www.tenable.com/security/research/tra-2026-66"},{"url":"https://github.com/go-chi/chi/security/advisories/GHSA-j6qf-3m9c-vwj3"}],"tags":["cve.org","exploit-available"],"ingestedAt":"2026-10-21T13:57:01.098Z","slug":"CVE-2026-114437","body":"## Overview\n\nIn the Golang Chi web framework, the ClientIPFromXFF middleware skips any X-Forwarded-For entry in a configured trusted CIDR but never verifies that the direct TCP peer in http.Request.RemoteAddr belongs to that CIDR. A client that can reach the Go server directly can therefore append a trusted-looking proxy address and choose the client IP returned by middleware.GetClientIP.\n\nThis issue affects chi before 5.4.0.\n\n## Affected\n\n- `github.com/go-chi/chi/v5 < 5.4.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":38,"depthScoreParts":{"impact":26.4,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[{"seq":227359,"id":"CVE-2026-114437","ts":1792606196342,"field":"exploit_available","old":"false","new":"true"}]}