{"cve":"CVE-2026-114437","nvd":{"published":"2026-10-21T14:17:14.690","modified":"2026-10-21T18:17:27.563","status":"Deferred","description":"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 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.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","score":6.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","score":4.8},"cwes":["CWE-348"],"references":["https://github.com/go-chi/chi/security/advisories/GHSA-j6qf-3m9c-vwj3","https://www.tenable.com/security/research/tra-2026-66"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:42:36.023364351+00:00"},"epss":{"cve":"CVE-2026-114437","score":0.00129,"percentile":0.02558,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-j6qf-3m9c-vwj3","url":"https://osv.dev/vulnerability/GHSA-j6qf-3m9c-vwj3","summary":"chi: Client IP spoofing in ClientIPFromXFF via X-Forwarded-For","modified":"2026-10-23T21:15:03.935320289Z","packages":[{"ecosystem":"Go","name":"github.com/go-chi/chi/v5","purl":"pkg:golang/github.com/go-chi/chi/v5","ranges":["<5.4.0"],"fixed":["5.4.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}