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.

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.

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.