The Registrations for the Events Calendar WordPress plugin before 2.13.4 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).

The Registrations for the Events Calendar WordPress plugin before 2.12.4 does not sanitise and escape some parameters when accepting event registrations, which could allow unauthenticated users to perform Cross-Site Scripting attacks.

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in Roundup WP Registrations for the Events Calendar allows SQL Injection.This issue affects Registrations for the Events Calendar: from n/a through 2.12.2.

The Registrations for the Events Calendar WordPress plugin before 2.7.10 does not escape the qtype parameter before outputting it back in an attribute in the settings page, leading to a Reflected Cross-Site Scripting

The Registrations for the Events Calendar WordPress plugin before 2.7.6 does not sanitise and escape the event_id in the rtec_send_unregister_link AJAX action (available to both unauthenticated and authenticated users) before using it in a SQL statement, leading to an unauthenticated SQL injection.

The Registrations for the Events Calendar WordPress plugin before 2.7.5 does not escape the v parameter before outputting it back in an attribute, leading to a Reflected Cross-Site Scripting