CVE-2026-120263 Details
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.
A vulnerability in Gitea's OAuth2 account linking feature allows an attacker to take over another user's account, including administrators, without knowing their password. This issue occurs when the 'ACCOUNT_LINKING' setting is set to 'auto' and registration is open. The vulnerability arises because the link-account sign-up form uses the username or email provided by the attacker to link accounts, rather than the identity verified by the OAuth2 provider. As a result, an attacker can link their external identity to a victim's account and gain access, with the link persisting for future logins. The vulnerability affects Gitea versions through 28.2.0 and has been patched in 28.3.0.
Users can upgrade to Gitea version 28.3.0, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Nov 1, 2026CISA-ADP
Assessed Nov 6, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://blog.gitea.com/release-of-28.3.0/ | Gitea Limited | Release NotesVendor |
| https://github.com/go-gitea/gitea/pull/40121 | Gitea Limited | Issue TrackingVendor |
| https://github.com/go-gitea/gitea/pull/40137 | Gitea Limited | Issue TrackingVendor |
| https://github.com/go-gitea/gitea/releases/tag/v28.3.0 | Gitea Limited | Release NotesVendor |
| https://github.com/go-gitea/gitea/security/advisories/GHSA-8p3x-w464-4g6v | Gitea Limited | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-287 | Improper Authentication | Gitea Limited |
| CWE-639 | Authorization Bypass Through User-Controlled Key | Gitea Limited |
Affected Products
| Product | Versions |
|---|---|
| Gitea | <= 28.2.0 (semver) v1.25.5 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 6, 2026 | CVE Modified | CISA-ADP |
| Nov 1, 2026 | New CVE Received | Gitea Limited |