500 error when request made with JWT missing aud claim

[JaredHatfield]

The request here is malformed.
The steps to reproduce is to generate a JWT that is missing the aud claim. Instead of getting the expected 400 or 403 error the API is returning a 500 error. It is likely that other missing required claims may be resulting in 500 errors as well.

Error: OAuth2 token endpoint returned status 500 Internal Server Error: {
  "error" : "server_error",
  "messages" : [ "Cannot invoke \"java.util.List.size()\" because \"aud\" is null" ],
  "status" : 500
}