MISP contains a reflected cross-site scripting (XSS) vulnerability in the AnalystDataController::viewForObject action. The method accepted a parent object type parameter from the URL without validation and passed it to the Overmind-themed AnalystData thread view element, where it was interpolated into two translated strings and rendered into the HTML response without output encoding. An authenticated attacker who can induce a victim to navigate to a crafted URL can inject arbitrary JavaScript that executes in the victim's browser within the MISP application context. This may allow the attacker to read session data, manipulate the page, or perform actions on behalf of the victim.  The vulnerability requires the victim to be authenticated to MISP and to actively visit the attacker-supplied URL. The affected component is the AnalystData controller and the Overmind theme's AnalystData thread element. Version affected: <2.5.47