There are a variety of mechanisms for staying up-to-date about new CircleCI releases. This includes checking the changelog and checking the Replicated Portal if on 3.x.
CircleCI's Server Changelog for Server 4.x
New releases are posted to our changelog once they are live. You can view that changelog here:
You can even subscribe to our RSS feed located at the top of the Changelog.
If a new version has been released and you'd like to update it, you can view our instructions here:
Using the Management Console for 3.x