{"id":"CVE-2026-120263","title":"Gitea OAuth2 account auto-linking takeover through the sign-up form","summary":"When `[oauth2_client].ACCOUNT_LINKING` is set to `auto` (not the default) and registration is enabled, the link-account sign-up form looked up the existing account to link by the user name or email submitted in the form instead of the id…","severity":"none","cwe":["CWE-287","CWE-639"],"vendor":"Gitea","product":"gitea.dev","affected":["gitea.dev < 28.3.0"],"published":"2026-11-01","updated":"2026-11-01","sourceUpdated":"2026-11-01T09:47:09.191Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-120263","references":[{"url":"https://github.com/go-gitea/gitea/security/advisories/GHSA-8p3x-w464-4g6v","label":"GitHub Security Advisory GHSA-8p3x-w464-4g6v"},{"url":"https://github.com/go-gitea/gitea/pull/40121","label":"Fix: go-gitea/gitea pull request #40121"},{"url":"https://github.com/go-gitea/gitea/pull/40137","label":"Fix backport to release/v28: go-gitea/gitea pull request #40137"},{"url":"https://blog.gitea.com/release-of-28.3.0/","label":"Gitea 28.3.0 release announcement"},{"url":"https://github.com/go-gitea/gitea/releases/tag/v28.3.0","label":"go-gitea/gitea v28.3.0 release"}],"tags":["cve.org"],"epss":0.00162,"epssPercentile":0.0547,"ingestedAt":"2026-11-05T18:28:50.700Z","slug":"CVE-2026-120263","body":"## Overview\n\nWhen `[oauth2_client].ACCOUNT_LINKING` is set to `auto` (not the default) and registration is enabled, the link-account sign-up form looked up the existing account to link by the user name or email submitted in the form instead of the identity asserted by the OAuth2 provider. An attacker with an account on a configured OAuth2 provider could submit another user's name, link their external identity to that Gitea account and be signed in as it without its password, including as an administrator. The link persisted for later sign-ins. Automatic linking now only happens when the existing account matches the provider's email or provider-derived user name; otherwise the account password is required.\n\n## Affected\n\n- `gitea.dev < 28.3.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}