The WP Booking System – Booking Calendar plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 2.1.0.3 This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for unauthenticated attackers to read the stored notification email body of any booking by iterating booking_id and email_log_id, exposing customer PII including names, email addresses, phone numbers, messages, and booking dates intended to be visible only to administrators. This is exploitable by any Subscriber-level user because admin_init fires on profile.php, a wp-admin page accessible to all authenticated users.