{"id":"CVE-2026-25779","aliases":["GHSA-j5r2-4c8j-xc3m","GO-2026-5448"],"url":"https://o3.security/vulnerability/CVE-2026-25779","summary":"Gitea redirect handling permits open redirects through backslash paths","details":"### Details\n\nDespite the validation within `urlIsRelative` in `modules/httplib/url.go`, an open redirect is still possible due to usage of directory traversal sequences plus a back-slash in the \"redirect_to\" parameter.\n\n### PoC\n\nWhen a user uses this URL to login:\n\n`https://gitea.com/user/login?redirect_to=/a/../\\example.com`\n\nThey would be redirected to `example.com` upon a successful login to their gitea account.\n\n### Impact\n\n* Phishing: Attackers can use trusted domain links to redirect victims to credential-harvesting pages\n* OAuth/SSO Token Theft: In authentication flows, authorization codes or tokens may leak via redirect\n* Referer Leakage: Sensitive URL parameters may be exposed to attacker domains via the Referer header\n* Cache Poisoning: In deployments with shared caches, malicious redirects may be cached and served to other users","published":"2026-07-03T20:19:33.452Z","modified":"2026-10-28T02:30:23.172388321Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":{"score":0.00344,"percentile":0.27185,"asOf":"2026-09-02"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/go-gitea/gitea","fixedVersion":"1.26.0"}],"fix":{"url":"https://github.com/go-gitea/gitea/pull/36660","label":"go-gitea/gitea#36660"},"references":[{"type":"ADVISORY","url":"https://blog.gitea.com/release-of-1.25.5/"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25779.json"},{"type":"ADVISORY","url":"https://github.com/go-gitea/gitea/releases/tag/v1.25.5"},{"type":"ADVISORY","url":"https://github.com/go-gitea/gitea/security/advisories/GHSA-j5r2-4c8j-xc3m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-25779"},{"type":"FIX","url":"https://github.com/go-gitea/gitea/pull/36660"},{"type":"FIX","url":"https://github.com/go-gitea/gitea/pull/36716"},{"type":"PACKAGE","url":"https://github.com/go-gitea/gitea"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:23.172388321Z"}}