Multiple plugins for WordPress are vulnerable to Stored Cross-Site Scripting via the plugin's bundled FancyBox JavaScript library (versions 1.3.4 to 3.5.7) in various versions 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.

The easy-fancybox plugin before 1.8.18 for WordPress (aka Easy FancyBox) is susceptible to Stored XSS in the Settings Menu inc/class-easyfancybox.php due to improper encoding of arbitrarily submitted settings parameters. This occurs because there is no inline styles output filter.