CVSSv3 Score: 5.9 An Improper Authentication vulnerability [CWE-287] in the FortiOS Remote Radius Type Admin Two-Factor (TFA) Authentication may allow a remote authenticated attacker with at least read-only permission to log in to the FortiOS GUI with an invalid token after entering a valid username and password, in scenarios where the RADIUS server returns an additional "Access-Challenge" response following an invalid TFA token. Revised on 2026-11-10 00:00:00