The update from macOS Tahoe 26.1 to 26.2 is fairly large, but appears to be largely routine maintenance, together with some important security updates.
At last, Apple has provided more detail of some of the improvements and changes in this summary. These include a new Edge Light feature to light your face during low-light video calls, Podcasts gaining automatic chapter generation, filters added to the Games library, AirDrop codes providing an additional means of verification with unknown contacts, and enhancements to Freeform tables.
Security release notes report a total of 46 vulnerabilities addressed. Among those are multiple WebKit vulnerabilities, including two that Apple believes have been exploited already “in an extremely sophisticated attack against specific targeted individuals” in earlier versions of iOS. Those alone make 26.2 a compelling early update.
The build number of macOS 26.2 is 25C56, it updates iBoot firmware to version 13822.61.10 on Apple silicon Macs and Intel firmware to 2094.40.1.0.0 (iBridge 23.16.12048.0.0,0). Note that Intel Macs only have an update to iBridge, and not their EFI firmware this time.
Significant changes seen in bundled apps include:
Freeform, to version 4.2
Music, to version 1.6.2
Passwords, to version 2.2
Safari, to version 26.2 (21623.1.14.11.9)
TV, to version 1.6.2.
Significant changes seen in /System/Library are relatively few, with many minor increments to build numbers. Notable changes include:
All AGX kernel extensions are updated
AppleDockConnect is a new kernel extension to accompany AppleDockChannel
AppleThunderboltRDMA is another new kernel extension
APFS is updated to version 2632.40.17, a tiny increment
the webcontentfilter kext has been removed
there is no change in the RichText.mdimporter for Spotlight indexing, implying that no bugs have been fixed in it.
The total number of bundles in that folder has only increased slightly, from 9785 to 9832.
One common criticism of the new Liquid Glass option added to Appearance settings in 26.1 is that Reduce transparency in Accessibility settings no longer reduces some transparency effects. There has been no change in that behaviour in 26.2, which continues to apply Liquid Glass effects in locations such as sidebars despite Reduce transparency being turned on. Our cries have clearly fallen on deaf ears.
I have also confirmed, as I suspected from the lack of change in the RichText.mdimporter, that the ‘LG bug’ in Spotlight remains, and still hasn’t been fixed.
In the early years of this blog, I used to keep track of some of the more serious bugs in macOS. As that developed into what would have occupied me full-time, I’ve cut back to try to cover some of the most significant. What has surprised me with macOS 26.1 is the sudden rush of new bugs in an update that’s normally expected to fix more than it creates. To consider what might have gone wrong, here’s an overview of those I’ve been investigating so far.
macOS virtualisation (new in 26.1)
A macOS 26.1 guest assigns itself a serial number of zero for the VM, whether the VM has been installed from the 26.1 IPSW image file, or updated from a previous version of macOS. This results in features that rely on the VM’s serial number to fail, the most important being access to iCloud.
Virtualisation is exceedingly complicated, and has suffered some previous accidents, such as the inability of M4 hosts running macOS 15.1 to virtualise guests with macOS earlier than 13.4. Although it’s easy to claim that better testing should detect these problems, the number of combinations of host Mac and macOS, and guest macOS increases their risk. Perhaps Apple should actively encourage third-party beta-testing in VMs.
Accessibility (new in 26.1)
macOS 26.1 introduces a new Appearance setting for Liquid Glass, but Apple hasn’t mentioned any change to the existing Reduce Transparency setting in Accessibility. However, that setting in 26.1 no longer disables Liquid Glass effects in sidebars and toolbars as it does in 26.0. User documentation for 26.1 is identical to that in macOS 15: Make transparent items solid Some windows and areas of the desktop, such as the Dock and menu bar, appear transparent by default. You can turn these transparent areas a solid grey to make it easier to distinguish them from the background.
This can be seen in the following screenshots.
This is 26.0 without Reduce Transparency.
This is 26.0 with Reduce Transparency turned on. Both the navigation sidebar and the window toolbar are completely opaque, and their contents are fully readable as a result.
This is 26.1 with Reduce Transparency turned on. Although the tools themselves are on opaque backgrounds, other areas remain partially transparent, and the toolbar in particular is visually cluttered and impairs accessibility.
Although this could be claimed to be intentional on Apple’s part, one visual feature that now appears when Reduce Transparency is turned on is the unreadable mess at the top of the System Settings window, where its search box overlays scrolling content in that sidebar.
If that’s intentional on Apple’s part, then macOS 26.1 is unsuitable for users with most forms of visual impairment, and many without.
Finder (new in 26.1)
In some Finder views, such as Column View, selecting an item at the left displays that item’s thumbnail and associated metadata. Below those are a selection of tools offering Finder services, such as Rotate Left, Markup, and more. Those are non-functional in 26.1, and if you want to use any of those services, you’ll have to use an alternative method, such as the contextual menu.
This is a strange bug, as it doesn’t occur in macOS VMs, suggesting there’s something more complicated going on. However, it’s also obvious, easy to test, and should never have survived into a release version of macOS.
Clock (macOS 15 and 26)
In macOS 15 and 26, including 26.1, the Clock app offers Timers that are implemented using the mobiletimerd service. The latter appears to hoard every past timer in its property list until that grows too large for the service to run, following which the feature fails to function.
According to Apple Support, an earlier bug in the mobiletimerd property list was fixed in macOS Sequoia. However, Apple is apparently unaware of the current problem. The current behaviour of mobiletimerd appears to be the result of poor design: if a service keeps adding more items to its property list, that will grow unconstrained, and sooner or later will cause this problem. It’s possible that fixing the previous bug may have resulted in the introduction of a new bug. Either way, this should have been detected long before it was released to the public.
Spotlight indexing (macOS 10.14 and later)
Since macOS Mojave, plain text files starting with certain characters don’t have their content indexed. Those files are correctly assigned to have their contents indexed by the macOS RichText mdimporter, according to their UTI. However, at the start of content indexing the text is checked for its ‘magic’ content. Those files that aren’t indexed because their opening bytes are recognised as being those of other types, and indexing is abandoned because of an error in the mdimporter. Examples of opening UTF-8 characters that can trigger this include the uncommon LG and HPA, and more common Draw.
This is the strangest bug among these, as the Rich Text mdimporter is supposed to index content according to the UTI of the file being indexed, which is being recognised correctly. There should be no need to perform another less reliable method of file type recognition using the ‘magic’ rules that is then causing content indexing to fail. That appears to have been introduced over seven years ago, but never tested adequately against a suitable search corpus.
The same mdimporter had suffered another bug that failed to index the content of any Rich Text file that was also undetected for over six months in 2020-21. Without thorough testing of mdimporters, further bugs are likely to occur in release code and remain undetected for long periods.
Conclusions
Of these five serious bugs in macOS 26.1, three are new to 26.1, one inherited from macOS 15, and one dates back seven years to macOS 10.14.
At least two of the five appear to have been introduced when trying to fix earlier bugs.
All five should have become obvious during testing, and none should have remained in any public release of macOS.
Both of the bugs that were inherited from macOS 15 appear to reflect flawed design.
Only one of the bugs, that in virtualisation, is noted in Apple’s developer release notes for 26.1, and that wasn’t carried forward to its release notes for users.
Acknowledgements
I’m very grateful to Rich Trouton, Michele, Paul, Jürgen, Drew, aldous and others who have provided invaluable information about these bugs.
You may have heard my deep sigh of disappointment last week when I looked through macOS Tahoe 26.1. Despite its bumper crop of 90 fixes for security vulnerabilities, as a scheduled update it has two major flaws. It is at once an opportunity ignored, and a failure to learn from history.
Liquid Glass
Ever since the first beta-release of Tahoe reached developers in June, its human interface has been lambasted like no other. Apple has had a torrent of objections to several of its new features, including the gross rounding of corners of windows and controls, its bland and indistinguishable icons, interference between overlaid content, and its uniform bleached-out tone. In those five months, there has been no shortage of suggestions as to what needs to be improved.
Apple’s response is a Liquid Glass control in Appearance settings that purports to provide a “tinted” variant that “increases opacity and adds more contrast”. As I demonstrated early last week, it does neither, and in Light mode in the great majority of Apple’s own apps, this “tinted” variant doesn’t make a blind difference.
Above is Light mode, Liquid Glass set Clear, without Accessibility. Below is the same, but with Liquid Glass set to Tinted.
After many attempts to find some difference between Clear and Tinted in the bundled apps I use most often, I’ve decided that they are visually identical. And where the Liquid Glass effect results in optical interference between layers, Tinted doesn’t alter opacity to eliminate that interference.
This is illustrated in the defaced search box at the top left of System Settings, where the blurred contents of the navigation sidebar at the left remain visible underneath the window’s search box. I can’t understand how any designer could see that released to the public, and providing the new Liquid Glass setting is farting into a hurricane.
Background Security Improvements
Although Apple went out of its way not to let us know, I’m actually glad to see the return of Rapid Security Responses (RSR), even if they’ve been given this sanitised name. What disappoints me deeply is that the BSI shows no sign that Apple has learned from its past mistakes with RSRs just over two years ago.
RSRs, which have never been officially declared dead, were downloaded through Software Update, and gave the user the choice of installing them automatically, downloading and installing them when they chose to, or ignoring them and waiting for the next macOS update. Not only that, but once installed, they could be removed and macOS reverted to its previous state.
What Apple never did get right is how to number the macOS version once an RSR had been installed. Rather than extend version numbers consistently with a fourth digit, Apple decided to append a letter in parentheses, making 13.4.1 become 13.4.1 (a) when its first RSR had been installed. When the first RSR was released on 1 May 2023, Safari’s build number was changed, but not its version number. But with the second RSR on 10 July, someone mistakenly changed Safari’s version number from 16.5.1 to 16.5.2 (a), and that was therefore given as its User Agent, and promptly broke many major websites including Facebook.
Because that RSR could be removed by the user, there was an immediate solution, and Apple delivered a revised RSR a couple of days later.
From this, we learned that:
RSRs undergo very little testing before release, as they’re supposed to be issued quickly.
Because they undergo such little testing, their chances of significant incompatibilities are greater.
Giving the user the option to delay installing an RSR saves many from being caught out by flawed RSRs.
Giving the user the option to uninstall an RSR is essential in the event that one proves to be flawed.
Knowing when an RSR is being installed is essential if users are going to be able to identify the cause of problems arising from them.
Numbering of macOS versions needs to be restructured to accommodate RSRs.
Now, over two years later, it seems Apple has forgotten those lessons. It won’t even describe these as security updates, but “improvements”, won’t include them in the release notes for 26.1, hides their single control at the very bottom of a long list in Privacy & Security settings, rather than in Software Update, provides no manual option, and no means to uninstall them.
I wonder how long it will be before we all regret those decisions, and have to repeat past mistakes before we can learn from them.
When Apple released macOS 26 Tahoe I published an article exploring how you can configure its redesigned interface, using its additional variations to appearance modes and its new Liquid Glass effects. When Tahoe 26.1 was released a couple of days ago, it changed those by adding a new control for those Liquid Glass visual effects. This article shows how that might change your options.
There are now four sets of controls:
Appearance mode, Light or Dark, in Appearance settings;
Liquid Glass setting, Clear or Tinted, in Appearance settings;
Display variations to Reduce transparency or Increase contrast, in Accessibility settings;
Icon & widget style, in Appearance settings.
Apple’s descriptions of the two states for Liquid Glass read:
“Clear is more transparent, revealing the content beneath.”
“Tinted increases opacity and adds more contrast.”
Those terms indicate an overlap with Accessibility settings. However, if either of the Accessibility settings is enabled, then the Liquid Glass setting is unavailable. I also presume that the word tinted here refers to the faint colouration that might be seen in what would otherwise be a transparent view, rather than any more generalised addition of colour.
Light mode
There are four overall variations of light mode, depending on Liquid Glass and Accessibility settings.
The starting point and default is in light mode, Liquid Glass clear, without Accessibility, and icon & widget style set to Default. Note the effects of transparency on the menu bar, widgets, the Liquid Glass effect in the left side of the Dock, and the upper row of icons in the Finder window. If you like those, you don’t have to change any settings.
This is the same, but with Liquid Glass set to Tinted. I’m unable to see any difference between those settings in this example.
This is light mode with Reduce transparency enabled in Accessibility settings. This disables all Liquid Glass effects and restores the traditional menu bar and Dock. The effect on Desktop widgets is perhaps less beneficial.
In light mode with Increase contrast (automatically coupled with Reduce transparency) enabled, the predominant effect is the outlining of controls within each window, rather than any change in contrast. Colours used by the system, such as the traffic light controls at the top left of each window, and those in themes, are darker, but those elsewhere, as in icons, aren’t changed. The effect here is to make controls clearer rather than actually changing contrast.
Dark mode
Without changing Accessibility and leaving Icon & widget style set to Default, and Liquid Glass set to Clear, dark mode shows transparency and Liquid Glass effects as you expect. These are again most visible in the menu bar, Dock, and the upper row of icons in the Finder window.
This is the same, but with Liquid Glass set to Tinted. Two most obvious differences are seen in the back-forward controls by the title of the Appearance settings, which oddly appears white, and the widgets, which are much darker. There are some inconsistent differences in the toolbar of the Finder and Tips windows, but they are more subtle.
With Reduce transparency enabled in Accessibility settings those transparency and Liquid Glass effects are removed.
Enabling Increase contrast outlines controls clearly, but any changes in system colours are more variable than in light mode.
Icon & widget style
This is new to Tahoe and only affects the rendering of icons and widgets. Liquid Glass settings don’t appear to have any effect on these.
Using light mode without any Accessibility changes, the Default setting for Icon & widget style is the baseline, showing icons in their ‘normal’ state.
Dark icon settings in light mode contrasts more but their readability may suffer.
When Icon & widget style is set to Clear, most are decolourised, making them significantly harder to read, and impossible to distinguish in the sidebar of System Settings.
The final option is for Icon & widget style to be Tinted (no relation to the Liquid Glass setting Tinted), where they’re rendered in monochrome using a colour of your choice, selected from the popup menu below. On iPhones and other devices that are available in several case colours, some have decided to set tinting to match the case, something you might like to try with an Apple silicon iMac, for example.
However, be careful in both Clear and Tinted styles, as it’s easy to end up making many icons unreadable and almost indistinguishable, here by setting the last of those to Graphite colour. This is one of the obvious drawbacks in Tahoe’s flexibility, in that many combinations of appearance mode, Accessibility settings and icon and widget style degrade its human interface rather than enhancing it. At least you now know what not to try, and how to return it to its defaults.
Summary of controls
Appearance mode, Light or Dark, in Appearance settings;
Liquid Glass, Clear or Tinted, in Appearance settings;
Display variations to Reduce transparency or Increase contrast, in Accessibility settings, but those automatically override Liquid Glass settings;
Icon & widget styles, in Appearance settings, with Icon, widget & folder colour when appropriate.
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