In Apache NiFi before 1.0.1 and 1.1.x before 1.1.1, there is a cross-site scripting vulnerability in connection details dialog when accessed by an authorized user. The user supplied text was not being properly handled when added to the DOM.
In Apache NiFi before 0.7.4 and 1.x before 1.3.0, there are certain user input components in the UI which had been guarding for some forms of XSS issues but were insufficient.