For once, Apple’s bland statement that “this update provides important bug fixes and security updates” may be the best overview of what has changed in macOS Tahoe 26.3. There are few version changes that stand out, but a lot of smallish build increments that suggest some bugs, at least, have been fixed.

Security is another matter, with around 52 vulnerabilities addressed and listed here. Those include one that Apple reports has been exploited in a sophisticated attack against an older version of iOS. For that alone, this update is compelling if you’ve already upgraded to Tahoe.

There are three entries in Apple’s release notes for enterprise, although none should affect those outside enterprise environments.

What Apple doesn’t reveal is that it has improved, if not fixed, the shortcomings in Accessibility’s Reduced Transparency setting. When that’s enabled, at least some of the visual mess resulting from Liquid Glass, for example in the Search box in System Settings, is now cleaned up, as the sidebar header is now opaque. It’s a small step, but does address one of the most glaring faults in 26.2.

The build number of the release version of 26.3 is 25D125. There are firmware updates all round, bringing iBoot to 13822.81.10, and Intel T2 firmware to 2094.80.5.0.0 with iBridge 23.16.13120.0.0,0.

Significant version increments in bundled applications include:

• Freeform from 4.2 (630.61.2) to 4.3 (630.81.1)
• Music from 1.6.2 to 1.6.3
• Passwords from 2.2 (21623.1.14.11.9) to 2.3 (21623.2.7.11.6)
• Safari from 26.2 (21623.1.14.11.9) to 26.3 (21623.2.7.11.6)
• TV from 1.6.2 to 1.6.3.

Significant changes seen in /System/Library include:

• PosterBoard app has been removed from CoreServices
• Kernel extensions in the AGX family have substantial changes in build numbers
• AppleT6022CLPCServer has been added as a new kext
• There are two new kexts to support Thunderbolt, AppleThunderboltUSBType2DownAdapter and AppleThunderboltUSBType2UpAdapter, perhaps to support new hardware features in future M5 models?
• APFS from version 2632.40.17 to 2632.80.1
• MPSHost, a new framework for Metal performance shaders, has been added
• New private frameworks include BinaryAssetTag
• Spotlight mdimporters updated to new build numbers include Application, Automator, CoreMedia and Mail, but not RichText.

I look forward to hearing of any fixes or improvements you find.