The Grid Plus plugin for WordPress is vulnerable to Local File Inclusion in versions up to, and including, 1.3.2 via a shortcode attribute. This allows subscriber-level, and above, attackers 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 PHP files with arbitrary content can be uploaded and included. This is limited to .php files.
https://plugins.trac.wordpress.org/browser/grid-plus/tags/1.3.2/core/grid.plus.base.class.php#L19