CVE Catalog

CVE-2025-68481

MediumCVSS 5.9
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.26%

16th percentile - higher than 16% of all known CVEs

Summary

FastAPI Users prior to version 15.0.2 has a login CSRF vulnerability due to stateless OAuth state tokens that are not linked to the initiating session. An attacker can exploit this to take over the victim's account or log the victim into the attacker's account.

Risk Assessment

An attacker can perform a login CSRF attack, potentially leading to account takeover or unauthorized access to data, posing a serious risk to the organization.

Recommendation

Upgrade FastAPI Users to version 15.0.2 or later, which includes a patch.

Related vulnerabilities

Original NVD description (English source)

FastAPI Users allows users to quickly add a registration and authentication system to their FastAPI project. Prior to version 15.0.2, the OAuth login state tokens are completely stateless and carry no per-request entropy or any data that could link them to the session that initiated the OAuth flow. `generate_state_token()` is always called with an empty `state_data` dict, so the resulting JWT only contains the fixed audience claim plus an expiration timestamp. On callback, the library merely checks that the JWT verifies under `state_secret` and is unexpired; there is no attempt to match the state value to the browser that initiated the OAuth request, no correlation cookie, and no server-side cache. Any attacker can hit `/authorize`, capture the server-generated state, finish the upstream OAuth flow with their own provider account, and then trick a victim into loading `.../callback?code=<attacker_code>&state=<attacker_state>`. Because the state JWT is valid for any client for \~1 hour, the victim’s browser will complete the flow. This leads to login CSRF. Depending on the app’s logic, the login CSRF can lead to an account takeover of the victim account or to the victim user getting logged in to the attacker's account. Version 15.0.2 contains a patch for the issue.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS