The Booking Calendar and Notification plugin for WordPress is vulnerable to unauthorized access, modification, and loss of data due to missing capability checks on the wpcb_all_bookings(), wpcb_update_booking_post(), and wpcb_delete_posts() functions in all versions up to, and including, 4.0.3. This makes it possible for unauthenticated attackers to extract data, create or update bookings, or delete arbitrary posts.