The Falang multilanguage for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'falang_term[<taxonomy>][<locale>][<field>] (via order[] driving wp_update_term)' parameter in all versions up to, and including, 1.4.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit is made reliable because the required 'falang' nonce is disclosed to any logged-in user through the equally unprotected wp_ajax_falang_menu_translation handler, requiring no elevated access to obtain.