The Ultimate Addons for Elementor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Navigation Menu Widget data-toggle-icon/data-close-icon Attributes in all versions up to, and including, 2.9.1 due to insufficient input sanitization and output escaping. 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. wp_kses_post, applied on save for users without unfiltered_html, does not neutralize HTML-entity-encoded payloads stored inside data-* attributes on kses-allowed elements, as the browser decodes these values client-side before jQuery .html() renders them as markup.