You are living very dangerously and running 2 whole major versions back. The only Apple Operating Systems (macOS, iOS, etc.) that have both the latest Platform Security features and get 100% of security patches is the very latest version.

This is well known within both the security community and Mac Sys Admin community.

Thanks, I’m realizing that now. It helps that you’re emphasizing the need to stay up to date.

I don’t upgrade to the latest version when it comes out thinking it may not be stable enough yet. And then I remember about it when I’m about to start working or in the flow. I know, silly excuses!

And for some reason I used to think security patches get back ported to all the supported versions and by not upgrading I was only missing out on new features.

Thanks for letting me know that’s not correct!