The Lightbox & Modal Popup WordPress Plugin – FooBox plugin for WordPress is vulnerable to DOM-based Stored Cross-Site Scripting via HTML data attributes in all versions up to, and including, 2.7.28 due to insufficient input sanitization and output escaping on user supplied attributes. 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.