Gitea OAuth2 account auto-linking takeover through the sign-up form
Summary
| CVE | CVE-2026-120263 |
|---|---|
| State | PUBLISHED |
| Assigner | Gitea |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-01 10:18:37 UTC |
| Updated | 2026-11-01 10:18:37 UTC |
| Description | 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 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. |
Risk And Classification
EPSS: 0.001620000 probability, percentile 0.054030000 (date 2026-11-02)
Problem Types: CWE-287 | CWE-639 | CWE-287 CWE-287: Improper Authentication | CWE-639 CWE-639: Authorization Bypass Through User-Controlled Key
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| blog.gitea.com/release-of-28.3.0 | 88ee5874-cf24-4952-aea0-31affedb7ff2 | blog.gitea.com | |
| github.com/go-gitea/gitea/pull/40121 | 88ee5874-cf24-4952-aea0-31affedb7ff2 | github.com | |
| github.com/go-gitea/gitea/security/advisories/GHSA-8p3x-w464-4g6v | 88ee5874-cf24-4952-aea0-31affedb7ff2 | github.com | |
| github.com/go-gitea/gitea/releases/tag/v28.3.0 | 88ee5874-cf24-4952-aea0-31affedb7ff2 | github.com | |
| github.com/go-gitea/gitea/pull/40137 | 88ee5874-cf24-4952-aea0-31affedb7ff2 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: https://github.com/adrian-doyensec (en)
CNA: https://github.com/AdamKorcz (en)
CNA: https://github.com/DshtAnger (en)
CNA: https://github.com/ivantsepp (en)
CNA: https://github.com/bircni (en)
There are currently no legacy QID mappings associated with this CVE.