FacturaScripts contains a critical authentication bypass vulnerability in its two-factor authentication (2FA) validation endpoint. The endpoint accepts unauthenticated POST requests with only a username and TOTP code, without verifying the user's password or requiring CSRF protection. It also lacks rate limiting, allowing brute force attacks against the 2FA codes. Due to an extended verification window, multiple valid codes exist simultaneously, making brute forcing feasible within minutes. Successful exploitation results in complete account takeover of any 2FA-enabled user, including administrators. The vulnerability affects versions prior to 2026.3 and has a CVSS 4.0 base score of 9.3 (critical).