{"id":"CVE-2026-20896","aliases":["GHSA-f75j-4cw6-rmx4","GO-2026-6051"],"url":"https://o3.security/vulnerability/CVE-2026-20896","summary":"Gitea Docker image trusts spoofable reverse-proxy headers by default","details":"Gitea Docker image versions up to and including 1.26.2 use REVERSE_PROXY_TRUSTED_PROXIES=* by default, allowing any source IP to impersonate a user when reverse-proxy authentication headers such as X-WEBAUTH-USER are enabled.","published":"2026-07-03T20:19:29.588Z","modified":"2026-08-12T03:51:22.462345958Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":3,"affectedPackages":[{"ecosystem":"Go","name":"code.gitea.io/gitea","fixedVersion":"1.26.3"}],"fix":{"url":"https://github.com/go-gitea/gitea/pull/38151","label":"go-gitea/gitea#38151"},"references":[{"type":"ADVISORY","url":"https://blog.gitea.com/release-of-1.26.3-and-1.26.4/"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/20xxx/CVE-2026-20896.json"},{"type":"ADVISORY","url":"https://github.com/go-gitea/gitea/releases/tag/v1.26.3"},{"type":"ADVISORY","url":"https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20896"},{"type":"FIX","url":"https://github.com/go-gitea/gitea/pull/38151"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:22.462345958Z"}}