{"id":"CVE-2026-72815","aliases":["GHSA-3fxj-6jh8-hvhx","GO-2026-5774"],"url":"https://o3.security/vulnerability/CVE-2026-72815","summary":"go-chi chi v5.2.1 IP Spoofing via X-Forwarded-For Header","details":"go-chi chi versions >= 5.2.1 and before 5.3.0 contain an IP spoofing vulnerability in the RealIP middleware, which blindly trusts the first (leftmost) value of the X-Forwarded-For HTTP header. A remote attacker can bypass IP-based access control lists and rate-limiting mechanisms, and forge log entries, by supplying a spoofed IP address in the X-Forwarded-For header. The issue is fixed in version 5.3.0.","published":"2026-08-14T11:35:27.496Z","modified":"2026-08-28T17:40:53.068388726Z","cvss":null,"epss":{"score":0.00397,"percentile":0.32996,"asOf":"2026-09-08"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/go-chi/chi/v5/middleware","fixedVersion":"5.3.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72815.json"},{"type":"ADVISORY","url":"https://github.com/go-chi/chi/security/advisories/GHSA-3fxj-6jh8-hvhx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72815"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/go-chi-chi-ip-spoofing-via-x-forwarded-for-header"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-28T17:40:53.068388726Z"}}