Apple has released a Supplemental Update for macOS High Sierra 10.13.3.
The small system software update includes a patch aimed at addressing an unusual bug that could potentially cause a Mac app to unexpectedly crash when receiving a particular Telugu character.
Additionally, Apple has released iOS 11.2.6 along with updates to watchOS and tvOS to address the same bug for iPhone, iPad, Apple Watch, and Apple TV.
Installing macOS 10.13.3 Supplemental Update
The simplest way to install macOS 10.13.3 High Sierra Supplemental Update is through the Mac App Store:
- Go tot he Apple menu and choose “App Store”
- Go the Updates tab and install macOS High Sierra 10.13.3 Supplemental Update
Always back up a Mac with Time Machine or your backup method of choice before installing any system software update.
High Sierra users can also choose to download the Supplemental Update as a separate package installer from Apple support downloads:
- MacOS High Sierra 10.13.3 Supplemental Update for Macs other than iMac Pro
- MacOS High Sierra 10.13.3 Supplemental Update for iMac Pro
Mac users must be running macOS High Sierra to find the MacOS High Sierra 10.13.3 Supplemental Update available to download. The bug being patched apparently does not impact earlier versions of Mac OS system software, and so presumably no such patch will be released for those versions.
Separately, Apple released iOS 11.2.6 for iPhone and iPad with a patch for the same bug, along with tvOS 11.2.6 and watchOS 4.2.4, each with the Telugu character bug fix as well.