{"id":"CVE-2026-72815","summary":"go-chi chi v5.2.1 IP Spoofing via X-Forwarded-For Header","details":"go-chi chi versions \u003e= 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.","aliases":["GHSA-3fxj-6jh8-hvhx","GO-2026-5774"],"modified":"2026-08-18T12:57:54.542203445Z","published":"2026-08-14T11:35:27.496Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72815.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-290"]},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/go-chi/chi","events":[{"introduced":"71307f9b7e4e9527638bc951c42b782cd1560331"},{"fixed":"3b171578ca44dfd75ca3c5cbddc7b44c600a7b49"}],"database_specific":{"source":["AFFECTED_FIELD","DESCRIPTION"],"extracted_events":[{"introduced":"5.2.1"},{"fixed":"5.3.0"},{"introduced":"0"}]}}],"versions":["v5.2.5","v5.2.4","v5.2.3","v5.2.2","v5.2.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72815.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"}]}