The Event Tickets and Registration WordPress plugin before 5.8.1, Events Tickets Plus WordPress plugin before 5.9.1 does not prevent users with at least the contributor role from leaking the existence of certain events they shouldn't have access to. (e.g. draft, private, pending review, pw-protected, and trashed events).
https://wpscan.com/vulnerability/d80dfe2f-207d-4cdf-8c71-27936c6318e5/