Setup Wizard hangs if confirm password is incorrect while creating admin user

How to reproduce

• Start a new Jenkins instance.
• Enter the unlock code
• Install plugins (or not)
• On the create admin user page, enter two different values for password and confirm password
• Click Save and Finish

The buttons are greyed out and nothing happens.

Workaround

Reload the page.

What should happen instead?

A validation error should be displayed in the form and it should be possible to fix the form then submit again