Progress Sitefinity 9.1 has XSS via file upload, because JavaScript code in an HTML file has the same origin as the application's own code. This is fixed in 10.1.
Authenticate/SWT in Progress Sitefinity 9.1 has an open redirect issue in which an authentication token is sent to the redirection target, if the target is specified using a certain %40 syntax. This is fixed in 10.1.
Progress Sitefinity 9.1 uses wrap_access_token as a non-expiring authentication token that remains valid after a password change or a session termination. Also, it is transmitted as a GET parameter. This is fixed in 10.1.
Sitefinity 5.1, 5.2, 5.3, 5.4, 6.x, 7.x, 8.x, 9.x, and 10.x allow remote attackers to bypass authentication and consequently cause a denial of service on load balanced sites or gain privileges via vectors related to weak cryptography.
Telerik.Web.UI.dll in Progress Telerik UI for ASP.NET AJAX before R2 2017 SP1 and Sitefinity before 10.0.6412.0 does not properly protect Telerik.Web.UI.DialogParametersEncryptionKey or the MachineKey, which makes it easier for remote attackers to defeat cryptographic protection mechanisms, leading to a MachineKey leak, arbitrary file uploads or downloads, XSS, or ASP.NET ViewState compromise.