Flexi Product Slider and Grid for WooCommerce <= 1.0.5 - Authenticated (Contributor+) Local File Inclusion via 'theme' Shortcode Attribute

The Flexi Product Slider and Grid for WooCommerce plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 1.0.5 via the `flexipsg_carousel` shortcode. This is due to the `theme` parameter being directly concatenated into a file path without proper sanitization or validation, allowing directory traversal. This makes it possible for authenticated attackers, with Contributor-level access and above, to include and execute arbitrary PHP files on the server via the `theme` parameter granted they can create posts with shortcodes.