Running heroku update says you are already on the latest version while every command still warns that a newer version is available. One common cause is a stale local version cache: the CLI checks a cached latest-version file, and that cache can keep announcing a release that was rolled back or that your install channel never received. A Heroku team member confirmed the fix is to force a refresh of that cache, and the reporter later confirmed the warning stopped appearing. When the warning comes from an install channel that no longer publishes updates (snap, for example), the real fix is reinstalling through a supported channel like apt.