The Online Scheduling and Appointment Booking System WordPress plugin before 28.2 does not verify that the requester owns the AI booking-assistant conversation named in its unauthenticated conversation actions, allowing any unauthenticated visitor to read another visitor's assistant messages and to inject messages into their in-progress conversation.
https://wpscan.com/vulnerability/9eef3086-3a67-4ee2-bd78-e346e7b05d62/