It is understandable that you are concerned about that message, BrnGrh. We would be equally concerned about it. When did this first show up on your device? What, if any, other callouts were shown by the Device Health Check? Has your device been doing anything strange lately? If so, please share details.
I sent an email to the MyVerizon app developers. They responded that the problem is a messaging error from the app and my phone is not actually rooted. They stated this will be fixed within a few days.