Advantech WISE-DeviceOn Server versions prior to 5.4 contain a stored cross-site scripting (XSS) vulnerability in the /rmm/v1/dog/{agentId} endpoint. When an authenticated user adds or edits Software Watchdog process rules for an agent, the monitored process name is stored in the settings array and later rendered in the Software Watchdog UI without proper HTML sanitation. An attacker can inject malicious script into the process name, which is then executed in the browser context of users who view or interact with the affected rules, potentially enabling session compromise and unauthorized actions as the victim.