Input validation vulnerability in My Calendar 3.3.16

The My Calendar plugin for WordPress is vulnerable to a security issue. It is possible for someone with administrator-level permissions to inject malicious code into pages within the plugin. This malicious code will be executed whenever a user accesses the page, potentially allowing attackers to access sensitive information. This vulnerability affects versions of the plugin up to and including 3.3.16 due to a lack of input sanitization and output escaping.