Ultimate POS (Stock Management & Point of Sale) contains a stored cross-site scripting vulnerability that allows low-privileged authenticated attackers to inject arbitrary HTML and script markup by setting a malicious payload in the user first-name field during account creation. Attackers with a low-privileged role such as Cashier can submit a leave request through the HRM/Leave module, causing the unsanitized first-name markup to execute in the browser session of any higher-privileged user who views the leave-application notification pane, enabling cross-user session compromise within the admin origin.