The Themify Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'visible' Shortcode Attribute in all versions up to, and including, 7.8.2 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. This vulnerability is only exploitable when the 'slider' custom post type is active, which is satisfied automatically when the plugin is paired with a Themify theme or any other plugin that registers the 'slider' CPT.