Existing "elastic" user credentials continue to function after upgrading elasticsearch?

Hello, Team.

I understand that the elastic and kibana versions should be the same. Please verify.
Additionally, confirm
Existing "elastic" user credentials continue to work after elasticsearch is upgraded? Alternatively, should we generate new elastic user details for elasticsearch and kibana?

Please assist me in resolving my version issues.

Please read carefully the upgrade documentation before anything else.

In the case of running your own stack, the first sentence of the Upgrade Elastic on-prem is (bold is mine):

Once you are prepared to upgrade, you will need to upgrade each of your Elastic components individually.

As for the second question, no, you don't need to reset or change your passwords, they should work as usual after an upgrade.

Thanks @jsanz