Photo Gallery, Sliders, Proofing and Themes – NextGEN Gallery <= 3.59.12 - Authenticated (Contributor+) Local File Inclusion via 'template'

The Photo Gallery, Sliders, Proofing and Themes – NextGEN Gallery plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 3.59.12 via the 'template' shortcode parameter. This is due to insufficient path validation that allows absolute paths to be provided. This makes it possible for authenticated attackers, with Contributor-level access and above, to include and execute arbitrary PHP files on the server, bypassing web server restrictions like .htaccess. Successful exploitation could lead to information disclosure, code execution in the WordPress context, and potential remote code execution if combined with arbitrary file upload capabilities.