OctoPrint provides a web interface for controlling consumer 3D printers. Prior to 1.11.8 and 2.0.0rc3, Suppressed Command notification popups use PNotify rendering for printer-controlled payload.command and payload.message values in src/octoprint/static/js/app/viewmodels/terminal.js without HTML escaping. An attacker who convinces a victim to print a crafted file can inject HTML and JavaScript into the notification, disrupt prints, read information available to the victim including sensitive settings when permitted, or perform actions in the victim's OctoPrint session. This issue is fixed in versions 1.11.8 and 2.0.0rc3.