A cross-site scripting (xss) vulnerability exists in the add_alert_check page of Observium CE 24.4.13528. A specially crafted HTTP request can lead to a arbitrary javascript code execution. An authenticated user would need to click a malicious link provided by the attacker.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.