BOLO! Update your Apple operating software!
/Apple dropped a patch yesterday to fix a hole in it's software’s security.
In simple terms, as reported by Paul Wagenseil at Tom’s Guide webpage, ”a hacker could access your Mac from the internet and run malicious code or shut down legitimate applications. Needless to say, that is Very Bad.”
This includes your Apple computer and watch. It only includes you Apple phone or tablet if you are still using iOS 12.
Regardless, software updates are almost always a good thing (presuming you have good back-ups). Especially when the company calls it an ”emergency”!