The Royal Elementor Addons and Templates plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's Advanced Accordion widget in all versions up to, and including, 1.3.971 due to insufficient input sanitization and output escaping on user supplied attributes like 'accordion_title_tag'. 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.