Vulnerability · Published Dec 19, 2025 · Assigned by snyk
CVE-2025-14546
Medium 6.3
In plain English
A medium-severity security flaw in fastapi-sso. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Versions of the package fastapi-sso before 0.19.0 are vulnerable to Cross-site Request Forgery (CSRF) due to the improper validation of the OAuth state parameter during the authentication callback. While the get_login_url method allows for state generation, it does not persist the state or bind it to the user's session. Consequently, the verify_and_process method accepts the state received in the query parameters without verifying it against a trusted local value. This allows a remote attacker to trick a victim into visiting a malicious callback URL, which can result in the attacker's account being linked to the victim's internal account.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | fastapi-sso | 0.19.0 | GHSA-hp6r-r9vc-q8wx |
| PyPI | fastapi-sso | 0.19.0 | PYSEC-2026-1362 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| n/a | fastapi-sso | 0 – before 0.19.0 |
Weakness: CWE-285 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N/E:P