Cloudformation rule doesn't prevent stack creation

Hi,

Our cloudformation template requires user to enter the email, password and then confirm the password before creating the stack. We have cloudformation rule to check whether the password field and confirm password field are the same:

Rules:
  ConfirmPasswordsMatch:
    Assertions:
      - Assert:
          Fn::Equals:
            - !Ref AdminPassword
            - !Ref ConfirmAdminPassword
        AssertDescription: Passwords do not match

While it does render an error message below the password input field when two passwords are different, but it doesn't actually prevent user to create the stack. Even the password and confirm password are different, user can still successfully create the stack.

This is a blocker for us, because we want to use similar mechanism to validate other template parameters.

Using rule is the official validation mechanism , and we are doing in the same way.