EspoCRM 5.7.0 prior to 5.9.0 contains an authentication token reuse vulnerability that allows authenticated attackers to bypass two-factor authentication by exploiting token-to-password-hash mapping in application/Espo/Core/Utils/Authentication/Espo.php. Attackers can obtain an authentication token for a controlled account and replay it against any victim account sharing the same password, since tokens are bound to password hashes rather than unique per-user values, bypassing the victim's 2FA protections.