In some cases, they may simply be fixes, but in others they occur when Apple completely rewrites or replaces part of macOS. If that were true, wouldn’t it be better sticking with an older release with fewer bugs? There’s an obvious fallacy here in that this ignores the bugs which are fixed in a new release. Some like to point out that each new major, and many minor, version of macOS contains bugs, so the total number of bugs increases with each new release. For many, that may not include Catalina, because of its substantial architectural changes including the loss of 32-bit software support. Although it’s an unwritten rule that Apple only provides security updates for its current and last two major releases of macOS, you can be fairly certain that all remaining vulnerabilities in Sierra will now be left unpatched.Īs a general principle, you should run the most recent release of macOS that you can, without compromising what you do with your Mac. If you’re still running Sierra 10.12.6, your last Security Update was in late September last year, nearly six months ago.

In the next few weeks, Apple is likely to ship Catalina 10.15.4, which takes it a step closer to its end-point of 10.15.6 in the summer, and whatever 10.16 might bring later in the year. Now is a good time to re-evaluate which version of macOS your Macs are running.

Upgrade to el capitan vs sierra