When you build a .NET Framework application against a strong-named assembly, the application uses that version of the assembly at run time by default, even if a new version is available. However, you can configure the application to run against a newer version of the assembly. For details on how the runtime uses these files to determine which assembly version to use, see How the Runtime Locates Assemblies.
You can redirect more than one assembly version by including multiple bindingRedirect elements in a dependentAssembly element.
Explicit assembly binding redirection in an application configuration file requires a security permission. This applies to redirection of .NET Framework assemblies and assemblies from third parties. The permission is granted by setting the BindingRedirects flag on the SecurityPermission Class. For more information, see Assembly Binding Redirection Security Permission.