WPML Multilingual CMS <= 4.6.12 - Authenticated (Contributor+) Remote Code Execution via Twig Server-Side Template Injection

The WPML plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 4.6.12 via Twig Server-Side Template Injection. This is due to missing input validation and sanitization on the render function. This makes it possible for authenticated attackers, with Contributor-level access and above, to execute code on the server.