DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.1.0, arbitrary themes can be loaded through query parameters. If an installed theme had a vulnerability, even if it was not used on any page, this could be loaded on unsuspecting clients without knowledge of the site owner. This issue has been patched in version 10.1.0.

DNN allows loading unused themes on anonymous clients through query parameters