Apple has released Big Sur 11.3 update

Apple has just released the update to Big Sur 11.3. It’s huge: for M1 Macs, it weighs in at 6.62 GB and it’s around 6.2 GB for Intel models, making it the largest update to macOS since Mojave, and quite possibly the largest ever.

Among the many bugs which it fixes are a major security vulnerability explained in detail by Patrick Wardle. The message is clear that all Big Sur users should update as soon as they can.

Apple has provided the longest set of release notes for 11.3 that I can recall seeing for years! The full list includes:

  • Support for AirTags in Find My.
  • Improvements to running iOS/iPadOS apps on M1 Macs.
  • Enhanced emojis (well, there had to be some).
  • Improvements to Siri, Music, Podcasts, News, Safari, Reminders, support for two wireless controllers in gaming, hibernation support for M1 Macs, and more.
  • There are several significant bug fixes, including two for AirPods support, and full resolution on external 4K displays connected via USB-C.

There’s also improved support for SMB Multichannel, which Apple explains here. Additional release notes intended for system administrators are here.

Apple’s list of security fixes included in this update are here. This list contains more than fifty entries, includes several serious vulnerabilities, and five bugs in the kernel. And the Gatekeeper bypass detailed by Patrick Wardle.

Apple has also released the next Security Updates to Catalina (2021-002) and Mojave (2021-003). Standalone updaters for those have just been released, and are available from here for Catalina, and here for Mojave.

I suspect that most, if not all, models of Mac will have firmware updates following installation of macOS 11.3 or one of the security updates. I will update the list of versions accessed by SilentKnight as soon as I can, over the next day or two.

Those updating to macOS 11.3 may well notice that this downgrades XProtect from 2144 to 2143, and MRT from 1.77 to 1.75. Ensure that your Mac is updated again to their later versions, once the 11.3 update has been installed.

I’ll post more details later as they come in. Get updating!

Updated 1645 UTC 27 April with standalone installer links.