Umbraco, a free and open source .NET content management system, has a cross-site scripting vulnerability starting in version 14.0.0 and prior to versions 14.3.1 and 15.0.0. This can be leveraged to gain access to higher-privilege endpoints, e.g. if you get a user with admin privileges to run the code, you can potentially elevate all users and grant them admin privileges or access protected content. Versions 14.3.1 and 15.0.0 contain a patch. As a workaround, ensure that access to the Dictionary section is only granted to trusted users.