The Formidable Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via multiple parameters submitted during form entries like 'after_html' in versions before 2.05.03 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute in a victim's browser.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.