The Event Tickets and Registration plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.18.1 via the tc-order-id parameter due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to view order details of orders they did not place, which includes ticket prices, user emails and order date.
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).
The Events Tickets Plus WordPress plugin before 5.9.1 does not prevent users with at least the contributor role from leaking the attendees list on any post type regardless of status. (e.g. draft, private, pending review, password-protected, and trashed posts).
The Event Tickets and Registration plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the 'email' action in all versions up to, and including, 5.8.1. This makes it possible for authenticated attackers, with contributor-level access and above, to email the attendees list to themselves.
The Membership WordPress plugin before 3.2.3 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin
The GigPress WordPress plugin before 2.3.28 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks
CSV injection in the event-tickets (Event Tickets) plugin before 4.10.7.2 for WordPress exists via the "All Post> Ticketed > Attendees" Export Attendees feature.