The EventPrime – Events Calendar, Bookings and Tickets plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the em_ticket_category_data and em_ticket_individual_data parameters in all versions up to, and including, 4.0.7.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever an administrative user accesses an injected page. Note: this vulnerability requires the "Guest Submissions" setting to be enabled. It is disabled by default.