Snipe-IT v8.3.4 (build 20218) contains a reflected cross-site scripting (XSS) vulnerability in the CSV Import workflow. When an invalid CSV file is uploaded, the application returns a progress_message value that is rendered as raw HTML in the admin interface. An attacker can intercept and modify the POST /livewire/update request to inject arbitrary HTML or JavaScript into the progress_message. Because the server accepts the modified input without sanitization and reflects it back to the user, arbitrary JavaScript executes in the browser of any authenticated admin who views the import page. NOTE: this is disputed by the Supplier because the report only demonstrates that an authenticated user can choose to conduct a man-in-the-middle attack against himself.