The Master Addons For Elementor – Widgets, Extensions, Theme Builder, Popup Builder & Template Kits plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'jtlma_custom_js' Page Setting (Custom JS Extension) in all versions up to, and including, 3.1.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The unfiltered_html capability check is only enforced during Elementor control registration (UI rendering) and not during the save process, enabling Author-level users to inject the jtlma_custom_js setting directly via a crafted POST request to admin-ajax.php?action=elementor_ajax, bypassing the UI-level restriction entirely.