macOS Tahoe 26.0 Beta 1 – Everything You Need to Know!

macOS 26.0 (25A5279m) Beta 1 is now Available!

UPDATED: 6/09/25

This article will be continually updated as new information comes in.

Apple just released the first beta of macOS Tahoe Beta 1 update to developers! Let’s jump in and find out what’s new.

OpenCore Legacy Patcher for Unsupported Macs

OCLP 2.4.0 & macOS Tahoe 26 Beta 1 : DO NOT INSTALL NOT COMPATIBLE YET. This release is in full testing and it is not recommended that you attempt to instal lit yet.!

Kernel Debug Kit (KDK) Status:

macOS 26 Patch Notes Summary

  • 1. New Features/Improvements –
  • 2. Security Fixes –
  • 3. Enterprise Changes –
  • 4. Safari Security (Webkit) –
  • 5. Full installer & IPSW –
  • 6. Safari –
  • 7. OpenCore Legacy Patcher Users –

Full Apple Update Release list

macOS 💻 ✅

iOS 📲 ✅


  • Safari –
  • Xcode –
  • Command Line Tools for Xcode –

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Table of Contents

  • 1. Apple macOS Tahoe Links
  • 2. macOS 15 Final & Beta Release History
  • 3. macOS 15 Full Installer.app
  • 4. Apple Silicon M1 M2 & M3 IPSW Restore file Update
  • 5. macOS 15 Update sizes
  • 6. Apple Silicon System Firmware Version
  • 7. Apple Silicon OS loader Version (iBoot)
  • 8. Intel T2 BridgeOS Update
  • 9. Safari Update
  • 10. What’s new for enterprise in macOS 15
  • 11. Security Content of macOS 15
  • 12. macOS 15 Release Notes / Patch Notes / Changes

Click “Continue Reading” for the rest of the article.

1. Apple macOS Links

When Apple releases the official macOS Sequoia support links, they will be listed below.

  1. What’s new in the updates for macOS 15 – https://support.apple.com/en-us/HT213895
  2. What’s new for enterprise in macOS 15 – https://support.apple.com/en-us/HT213893
  3. Apple Security Updates Page – https://support.apple.com/en-us/HT201222
  4. macOS 15 Mac App Store link – https://apps.apple.com/us/app/macos-sonoma/id6450717509
  5. macOS 15 features page – https://www.apple.com/macos/sonoma/
  6. Manage upgrading to macOS Sonoma in your organization
  7. If you see a message that macOS Server is not supported when upgrading to macOS Sonoma
  8. Platform Security Guide – New macOS Rapid Security Response system.
  9. Platform Guide Deployment – What’s new in Apple platform deployment

AppleSeed Notes Link = appleseed.apple.com/

Developer Public Link = developer.apple.com/documentation/macos-release-notes

macOS Deployment References Changes – https://support.apple.com/guide/deployment-reference-macos/document-revision-history-apd04dff7069/web

3. macOS Tahoe Final & Beta Release History

  • 1. macOS 26 Beta 1 (25A5279m) – 6/09/25

4. macOS Tahoe Full Installer.app

Apple has released the full installer for macOS Sonoma. I list all the of the Full installers in the link below.

https://mrmacintosh.com/macos-tahoe-full-installer-database-download-directly-from-apple/

InstallAssistant.pkg = Full download. Installing this package will add the full “Install macOS Sonoma.app” to your applications folder.

5. Apple Silicon IPSW Restore file Update

Apple has released the full IPSW restore file of macOS for Apple Silicon M1 Macs. I keep track of all of them in my Apple Silicon Firmware Database

Get them here –> https://mrmacintosh.com/apple-silicon-m1-full-macos-restore-ipsw-firmware-files-database/

6. macOS Tahoe Update sizes

15 Delta Update

The delta update will automatically change in size for exactly what your macOS version needs.

Full update & OCLP Users =

Apple Silicon Updates

Delta from macOS Tahoe Beta 1 with size =

Intel Updates

Delta from macOS Tahoe Beta 1 with size =

Delta from macOS Tahoe Beta 1 with size =

7. Apple Silicon System Firmware Version

This update has a new firmware update. The version number is reported in System Information under “System Firmware Version“

Apple Silicon Firmware = Updated!

  • 1. macOS Tahoe Beta 1 =

8. Apple Silicon OS loader Version (iBoot)

OS Loader Version (iBoot) also referred to as “iBoot second-stage loader”, is Apple’s stage 2 bootloader. The OS loader version will be the same as the “System Firmware Version” on the latest OS. On previous versions of macOS Monterey and Big Sur, the OS loader version will be a version behind. Example = Monterey = 7459.121.3 & Big Sur = 6723.140.2

OS Loader version =

  • 1. macOS Tahoe Beta 1 =

9. Intel T2 BridgeOS Update

The Version of BridgeOS for your T2 Security Chip (2018-2020 Intel Macs) was updated.

BridgeOS version =

  • 1. macOS Tahoe Beta 1 =

10. Safari Update

The new version of Safari 18 is included in the macOS 15 update.

Safari =

  • 1. macOS Tahoe Beta 1 =

11. What’s new for Enterprise in macOS 26

Enterprise changes in macOS Tahoe beta 1

  • ?

https://support.apple.com/en-us/HT213893

12. Security Content of macOS Tahoe Beta 1

Security vulnerabilities in this Update

Fixes addressed in this update =

Safari 26.0 =

Webkit =

13. macOS Tahoe Beta Release Notes

https://developer.apple.com/documentation/macos-release-notes

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