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, 4.0.3 via the 'template' parameter in gallery shortcodes. This makes it possible for authenticated attackers, with Author-level access and above, to include and execute arbitrary .php 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 file types can be uploaded and included.

The Photo Gallery, Sliders, Proofing and Themes – NextGEN Gallery plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in the handlejob function in all versions up to, and including, 4.5.5 This makes it possible for authenticated attackers, with custom-level access and above, to delete arbitrary files on the server, which can easily lead to remote code execution when the right file is deleted (such as wp-config.php). The 'NextGEN Manage gallery' capability required to reach the vulnerable endpoint is granted to Administrators by default but can be delegated to lower-privileged roles via the plugin's Roles screen.