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.

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.

The WPML plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's wpmllanguageswitcher shortcode in versions 3.6.0 - 4.7.3 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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.

processforms in the WPML (aka sitepress-multilingual-cms) plugin through 3.6.3 for WordPress has XSS via any localefilename parameter (such as localefilenameen) in an authenticated theme-localization.php request to wp-admin/admin.php.

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.