The Events Calendar Made Simple – Pie Calendar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's piecal shortcode in all versions up to, and including, 1.2.5 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Freemius SDK, as used by hundreds of WordPress plugin and theme developers, was vulnerable to Cross-Site Request Forgery and Information disclosure due to missing capability checks and nonce protection on the _get_debug_log, _get_db_option, and the _set_db_option functions in versions up to, and including 2.4.2. Any WordPress plugin or theme running a version of Freemius less than 2.4.3 is vulnerable.

The Simple Calendar – Google Calendar Plugin plugin for WordPress is vulnerable to Reflected Cross-Site Scripting due to the use of add_query_arg without appropriate escaping on the URL in all versions up to, and including, 3.4.2. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

The WP Simple Booking Calendar plugin for WordPress is vulnerable to Reflected Cross-Site Scripting due to the use of add_query_arg & remove_query_arg without appropriate escaping on the URL in all versions up to, and including, 2.0.10. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

Cross-Site Request Forgery (CSRF) vulnerability in Veribo, Roland Murg WP Simple Booking Calendar.This issue affects WP Simple Booking Calendar: from n/a through 2.0.8.4.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Simple Calendar Simple Calendar – Google Calendar Plugin allows Stored XSS.This issue affects Simple Calendar – Google Calendar Plugin: from n/a through 3.2.6.

Cross-Site Request Forgery (CSRF) vulnerability in Simple Calendar – Google Calendar Plugin <= 3.2.5 versions.

The WP Simple Booking Calendar WordPress plugin before 2.0.6 did not escape, validate or sanitise the orderby parameter in its Search Calendars action, before using it in a SQL statement, leading to an authenticated SQL injection issue

The Simple Events Calendar WordPress plugin through 1.4.0 does not sanitise, validate or escape the event_id POST parameter before using it in a SQL statement when deleting events, leading to an authenticated SQL injection issue