Umbraco is an ASP.NET CMS used by more than 730.000 websites. Umbraco has an endpoint that is vulnerable to open redirects. The endpoint is protected so it requires the user to be signed into backoffice before the vulnerable is exposed. This vulnerability has been patched in version(s) 8.18.14, 10.8.6, 12.3.10 and 13.3.1.