CVE-2026-120263 Gitea OAuth2 account auto-linking takeover through the sign-up form
CriticalCVSS 9.8
EPSS 0.34%
- Published
- Updated
- Exploit status
- No public exploit known
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.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Gitea | < 28.3.0 | 28.3.0 |
References
- GitHub Security Advisory GHSA-8p3x-w464-4g6v vendor-advisory
- Fix: go-gitea/gitea pull request #40121 patch
- Fix backport to release/v28: go-gitea/gitea pull request #40137 patch
- Gitea 28.3.0 release announcement release-notes
- go-gitea/gitea v28.3.0 release release-notes