Fluent Booking < 2.1.2 - Calendar Manager+ Sensitive Information Disclosure via Attendee Export

The Fluent Booking WordPress plugin before 2.1.2 does not verify ownership of the requested group_id before exporting attendee data via the export endpoint, allowing users with at least the Calendar Manager role to retrieve attendees' PII (name, email, phone, address, payment information) from calendar groups they do not own.