The Booking Calendar plugin for WordPress is vulnerable to Missing Authorization leading to Sensitive Information Exposure in all versions up to, and including, 10.14.11. This makes it possible for authenticated attackers, with Subscriber-level access and above, to view all booking records in the database, including personally identifiable information (PII) such as names, email addresses, phone numbers, physical addresses, payment status, booking costs, and booking hashes belonging to other users.