CVE-2025-14546

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.

CVSS 4.0

5.4CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

CVSS 3.1

6.3CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 29% of CVEs (scores of 2026-10-25)

CWE

CWE-285

Published

2025-12-19

Modified

2026-10-13

Record from

the NVD, synced 2026-10-19

Packages (OSV)

References

• https://github.com/tomasvotava/fastapi-sso/commit/6117d1a5ad498ba57d671e8a059ebe20db5abe02
• https://github.com/tomasvotava/fastapi-sso/issues/266
• https://security.snyk.io/vuln/SNYK-PYTHON-FASTAPISSO-14386403

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