How-To & Tips

Security Update for macOS Tahoe 26.3.1 & iOS 26.3.1 Released

17 hours ago
2 minutes read
Security Improvement


Security Development

Apple has released what they call a “Security Update” as a software update for macOS Tahoe 26.3.1, iOS 26.3.1, and iPadOS 26.3.1. The update, bug, upgrade, is labeled as macOS Tahoe 26.3.1 (a), macOS 26.3.2 (a), iOS 26.3.1 (a), and iPadOS 26.3.1 (a), and although it’s included as a software update, you won’t find it available as one.

Surprisingly, “Security Updates” isn’t available through the regular Software Update mechanism on your Mac, iPhone, or iPad, so if you go to check there you won’t find any updates available. Instead, ‘upgrades’ are buried inside a completely separate section of settings where almost no user will look or accidentally stumble upon them. It would make more sense in my plebeian sense to place all system updates within the general “Software Update” section of settings, but here we are.

How to Download and Install Security Update for macOS Tahoe 26.3.1 (a)

Aside from being a security patch, it’s a good idea to back up your Mac with Time Machine before installing any software update:

  1. From the  Apple menu, select “System Preferences”
  2. Go to “Privacy and Security”
  3. See “Background Security Upgrades” for an update available there

You will need to have already installed macOS Tahoe 26.3.1 before the 26.3.1(a) “improvement” is available to you. If you don’t have the latest version installed on your Mac, you’ll see a message to install that update first, then you can get the upgrade.

Background on Mac Security ImprovementsBackground on Mac Security Improvements

Note that macOS 26.3.2 (a) is only available on MacBook Neo and possibly newer M5 Macs, so you won’t get that version if you’re on a different Mac.

How to download and install security updates for iOS 26.3.1 (a), and iPadOS 26.3.1 (a)

Make a backup before installing, as always:

  1. Open “System Settings”
  2. Go to “Privacy and Security”
  3. See “Background Security Upgrades” for an update available there

    4. Background Security Improvement is an update that can be called an update but requires a reboot to install as oneBackground Security Improvement is an update that can be called an update but requires a reboot to install as one

You will probably notice the “Background Security Updates” feature is enabled by default, where the update will install itself at the next available opportunity.

“Upgrading” requires an iPhone, iPad, or Mac to install to complete the installation of the review upgrade to your device.

Release Notes for iOS 26.3.1 (a), iPadOS 26.3.1 (a), macOS 26.3.1 (a), macOS 26.3.2 (a)

The release notes include a short and concise download:

This Backend Security Upgrade provides additional security and is recommended for all users.
For information about Background Security
For updates, please visit this website:

The web security notes have more details about the patched security issue:

Available for: iOS 26.3.1, iPadOS 26.3.1, macOS 26.3.1, macOS 26.3.2
Impact: Processing of poorly crafted web content may override the Same Origin Policy
Description: A cross-origin issue in the Navigation API was addressed with improved input validation.

Also, why Apple doesn’t just release this within the framework of “Software Update” to make it easier to find, install, and update, is a mystery, but since most users have the “Security Improvement” feature enabled by default on their Mac or iPhone, and the update will install automatically if possible, maybe it is not very necessary to update all the software under the middle of the OS.

Anyway, install updates on your devices.

17 hours ago
2 minutes read
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