How to avoid HttpRequestValidationException in ASP.NET MVC rendering the same view which caused the exception

With the latest version of ASP.NET MVC (the RC, at the time of writing this) you can just put an attribute on either your controller class or your action method, e.g.:

[ValidateInput(false)]
public ActionResult create()
{
    // ...method body
}

The ValidateInputAttribute is in System.Web.Mvc.

But as others have said, you do then have to perform your own manual input validation or cleaning.

Using MVC 3, you must also ensure this is in your Web.config: <system.web><httpRuntime requestValidationMode="2.0" /></system.web>