If there is a text binding to the item that has a script tag injected, the Core component will break its initialization instead of encoding it as it is done for the Telerik UI for ASP.NET MVC DropDownList helper.
@(Html.Kendo().DropDownList()
.Name("DDL")
.HtmlAttributes(new { style = "width:100%" })
.OptionLabel("Select...")
.DataTextField("text")
.DataValueField("value")
.Height(310)
.BindTo(new List<object> {
new { text = "Test", value = 0 },
new { text = "<script>alert(123)</script>", value = 0 }
})
)
Result: