CVE-2026-101023: code.gitea.io/gitea: Gitea: Prolonged access via improper OAuth2 token type validation

Severity: Critical

CVSS Score: 9.1

Gitea's OAuth2 token endpoint verified the signature and grant of a token submitted with the `refresh_token` grant type, but not that the token was a refresh token. An unexpired access token for the same OAuth2 application and grant could be exchanged for a new access token and refresh token. Whoever holds such an access token could keep access beyond the token's original lifetime.