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Vulnerability · Published Nov 1, 2026 · Assigned by Gitea

CVE-2026-120263Gitea OAuth2 account auto-linking takeover through the sign-up form

Unrated

In plain English

A improper authentication in Gitea from Gitea. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).

Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 94.5% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official 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 (as reported)

VendorProductVersions
Gitea Gitea 0 – before 28.3.0

Weakness: CWE-287, CWE-639

References