CVE-2025-14546
MEDIUMSeverity by source
CVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
2Blast Radius
ecosystem impact- 2 pypi packages depend on fastapi-sso (2 direct, 0 indirect)
Ecosystem-wide dependent count for version 0.19.0.
DescriptionCVE.org
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.
AnalysisAI
Account linkage via Cross-Site Request Forgery (CSRF) in fastapi-sso before 0.19.0 allows attackers to trick a victim into visiting a malicious callback URL that links the attacker's OAuth provider account to the victim's internal application account, granting the attacker unauthorized access. The vulnerability stems from missing state parameter validation during OAuth callback processing. A public proof-of-concept exists, but no active exploitation has been confirmed.
Same weakness CWE-285 – Improper Authorization
View allSame technique Authentication Bypass
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External POC / Exploit Code
Leaving vuln.today