Fluent Forms < 6.1.15 - Subscriber+ Stored XSS

Description

The plugin is vulnerable to Stored Cross-Site Scripting via the AI Form Builder module due to a combination of missing authorization checks, a leaked nonce, and insufficient input sanitization. The vulnerability allows Subscriber-level users to trigger AI form generation via a protected endpoint. When prompted, AI services will typically return bare JavaScript code (without <script> tags), which bypasses the plugin's sanitization. This stored JavaScript executes whenever anyone views the generated form, making it possible for authenticated attackers with Subscriber-level access and above to inject arbitrary web scripts that will execute in the context of any user accessing the form.