The Modern Events Calendar Lite WordPress plugin before 6.5.2 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 unfilteredhtml capability is disallowed (for example in multisite setup).

Cross-site scripting vulnerability in Modern Events Calendar Lite versions prior to 6.3.0 allows remote an authenticated attacker to inject an arbitrary script via unspecified vectors.

The Modern Events Calendar Lite WordPress plugin before 6.4.0 does not sanitize and escape some of the Hourly Schedule parameters which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks

The Modern Events Calendar Lite WordPress plugin before 6.2.0 alloed any logged-in user, even a subscriber user, may add a category whose parameters are incorrectly escaped in the admin panel, leading to stored XSS.

The Modern Events Calendar Lite WordPress plugin before 6.1.5 does not sanitise and escape the time parameter before using it in a SQL statement in the mecloadsinglepage AJAX action, available to unauthenticated users, leading to an unauthenticated SQL injection issue

The Modern Events Calendar Lite WordPress plugin before 6.1.5 does not sanitise and escape the currentmonthdivider parameter of its meclistloadmore AJAX call (available to both unauthenticated and authenticated users) before outputting it back in the response, leading to a Reflected Cross-Site Scripting issue

The Modern Events Calendar Lite WordPress plugin before 5.22.3 does not properly sanitize or escape values set by users with access to adjust settings withing wp-admin.

The Modern Events Calendar Lite WordPress plugin before 5.22.2 does not escape some of its settings before outputting them in attributes, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfilteredhtml capability is disallowed.