The WPML plugin before 3.1.9 for WordPress does not properly handle multiple actions in a request, which allows remote attackers to bypass nonce checks and perform arbitrary actions via a request containing an action POST parameter, an action GET parameter, and a valid nonce for the action GET parameter.

The "menu sync" function in the WPML plugin before 3.1.9 for WordPress allows remote attackers to delete arbitrary posts, pages, and menus via a crafted request to sitepress-multilingual-cms/menu/menus-sync.php.

SQL injection vulnerability in the WPML plugin before 3.1.9 for WordPress allows remote attackers to execute arbitrary SQL commands via the lang parameter in the HTTP Referer header in a wp-link-ajax action to comments/feed.

Cross-site scripting (XSS) vulnerability in the WPML plugin before 3.1.9 for WordPress allows remote attackers to inject arbitrary web script or HTML via the target parameter in a reminderpopup action to the default URI.