The LT Unleashed plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 1.1.1 via the 'template' parameter in the `book` shortcode due to insufficient path sanitization. This makes it possible for authenticated attackers, with Contributor-level access and above, to include and execute arbitrary files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where files such as wp-config.php can be included.