Drag and Drop Multiple File Upload PRO - Reflected Cross-Site Scripting

The Drag and Drop Multiple File Upload PRO - Contact Form 7 Standard WordPress plugin before 2.11.1 and Drag and Drop Multiple File Upload PRO - Contact Form 7 with Remote Storage Integrations WordPress plugin before 5.0.6.4 do not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high-privilege users such as admins.