The KiviCare – Clinic & Patient Management System (EHR) plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 4.1.2. This is due to the patientSocialLogin() function not verifying the social provider access token before authenticating a user. This makes it possible for unauthenticated attackers to log in as any patient registered on the system by providing only their email address and an arbitrary value for the access token, bypassing all credential verification. The attacker gains access to sensitive medical records, appointments, prescriptions, and billing information (PII/PHI breach). Additionally, authentication cookies are set before the role check, meaning the auth cookies for non-patient users (including administrators) are also set in the HTTP response headers, even though a 403 response is returned.