Gitea up to 28.2.x OAuth2 Userinfo Endpoint /login/oauth/userinfo improper authorization

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Gitea up to 28.2.x. The affected element is an unknown function of the file /login/oauth/userinfo of the component OAuth2 Userinfo Endpoint. Performing a manipulation results in improper authorization. This vulnerability was named CVE-2026-118394. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Gitea up to 28.2.x. This affects an unknown functionality of the file /login/oauth/userinfo of the component OAuth2 Userinfo Endpoint. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality. The summary by CVE is:

The OAuth2 userinfo endpoint (`/login/oauth/userinfo`) decided whether to limit the `groups` claim to public organizations by re-parsing the `Authorization` header as an OAuth2 access token instead of using the scope of the credential that authenticated the request. When a public-only OAuth2 token was sent as a query parameter or form field, or a public-only personal access token was used, that scope came back empty and the claim listed the token owner's private organizations, teams and concealed memberships. The disclosure is limited to the owner's organization and team names and memberships; no repository content is exposed. The endpoint now uses the scope of the authenticating token.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-118394 since 11/01/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading to version 28.3.0 eliminates this vulnerability.

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Productinfo

Name

• Gitea

Version

• 28.0
• 28.1
• 28.2

License

• open-source

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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