Flask-AppBuilder is an application development framework built on top of Flask python framework. In versions prior to 4.1.3 an authenticated Admin user could query other users by their salted and hashed passwords strings. These filters could be made by using partial hashed password strings. The response would not include the hashed passwords, but an attacker could infer partial password hashes and their respective users. This issue has been fixed in version 4.1.3. Users are advised to upgrade. There are no known workarounds for this issue.