The FundEngine – Donation and Crowdfunding Platform plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'wfp_featured_video_url' parameter in all versions up to, and including, 1.8.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The REST endpoint used to submit the video URL has its permission_callback set to __return_true, meaning any authenticated user — including those with Subscriber-level access — can reach the vulnerable code path.