OpenEMR 5.0.2 before 8.5.0 contains a missing authentication vulnerability in mfa_registrations.php and mfa_u2f.php that allows session hijackers to delete MFA factors or register U2F keys without password re-entry. Attackers holding a victim's authenticated session can remove all second factors or add their own U2F key, bypassing MFA at later logins with the password.