Contact Form Plugin by Fluent Forms for Quiz, Survey, and Drag & Drop WP Form Builder <= 5.2.6 - Unauthenticated Stored Cross-Site Scripting via Form Subject

The Contact Form Plugin by Fluent Forms for Quiz, Survey, and Drag & Drop WP Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the form's subject parameter in all versions up to, and including, 5.2.6 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.