The My Calendar WordPress plugin before 3.4.24 does not sanitise and escape some parameters, which could allow users with a role as low as Subscriber to perform Cross-Site Scripting attacks (depending on the permissions set by the admin)
The 'My Calendar' WordPress Plugin, version < 3.4.22 is affected by an unauthenticated SQL injection vulnerability in the 'from' and 'to' parameters in the '/my-calendar/v1/events' rest route.