<PackageReference Include="System.Security.Permissions" Version="10.0.0-rc.1.25451.107" />

AspNetHostingPermissionLevel

Specifies the trust level that is granted to an ASP.NET Web application.
namespace System.Web { public enum AspNetHostingPermissionLevel { None = 100, Minimal = 200, Low = 300, Medium = 400, High = 500, Unrestricted = 600 } }