Catalina 10.15.6 Supplemental Update (19G2021) Released!

macOS Catalina 10.15.6 Supplemental Update is now Available.

Today Apple released the 5th Supplemental Update for macOS Catalina. This time around, the fix is for memory leaks with virtualization software . You can read more about the issue from Howard Oakley and a VMware engineer. The other fix has to do with the brand new 2020 5k 27-inch iMac.

Build Version Number Mistake?

The Build version for this update is (19G2021). Normally a 4 digit end number on a macOS build version number means that it’s a “Forked” installer. A “Forked” installer means that it will ONLY install on brand new hardware from Apple. A perfect example of this is when Apple released the new 2020 iMac. It includes brand new hardware drivers that the previous builds of macOS didn’t include. To resolve this, Apple will release a full installer that has this new hardware included but will only install the new hardware. When a new dot release comes out, Apple will unify the installer so it can be install on any Mac including the new hardware. Tidbits has a great article that explains Apple build versions. The only problem is, the article does mention macOS hardware specific or forked build versions.

Below is a list of all the forked hardware specific installer build versions that Apple released for 10.15.

19B2093, 19B2106, 19D2064, 19E2269, 19F2096, 19F2200, 19G2005 & 19G2006

Below is a list of standard releases.

19B88, 19A603, 19A602, 19A583, 19C57, 19D76, 19E266, 19E287, 19F96, 19F101 & 19G73

Why did Apple give this unified installer a forked build version number (19G2021) ?

UPDATE: – Erik Gomez @Contains_ENG mentioned that 4 digit daily builds are common near the end of an OS release. Looking back at 10.13 and 10.14, this is true only when Apple starts to release 2020-001 type security updates. For example when Big Sur is released, Apple will stop working on bug fixes for Catalina and will only send out security updates. After the switch the build version usually makes the jump to 4 digits. I guess Apple decided to get a head start this year.

Unified 10.15.6 Full Installer

The good news about this update is that includes the 2 new BoardIDs for the 2020 iMacs. This means you do not have to keep a separate installer if you have any of the new iMacs in your fleet. The new installer (19G2021) will work on them.

The Catalina 10.15.6 Supplemental Update Includes the following fixes.

macOS Catalina 10.15.6 supplemental update includes big fixes for your Mac

• Fixes a stability issue that could occur when running virtualization apps
• Resolves an issue where an iMac (Retina 5k, 27-inch 2020) may appear washed out when waking from sleep.

Apple’s Public Patch Notes / Release Notes Documentation

NOTE: Apple Documentation takes a little while to show up online after release. I will update when the new articles are made available.

https://support.apple.com/en-us/HT210642

developer.apple.com/documentation/macos_release_notes

developer.apple.com/documentation/macos-release-notes/macos-catalina-10_15_6-release-notes

For more detailed information about this update and previous updates, please visit: https://support.apple.com/kb/HT210642

Previous 10.15 Releases + Previous Patch Notes

• 20. 10.15.6 = (19G2021) – Supplemental Update – Aug 12th 2020
• 19. 10.15.6 = (19G2006) – 2020 iMac Fork Re-Released – Aug 4th, 2020
• 18. 10.15.6 = (19G2005) – 2020 iMac Fork – Aug 4th, 2020
• 17. 10.15.6 = (19G73) – July 15th, 2020
• 16. 10.15.5 = (19F2200) – 16″ MBPro Update Fork – June 15th 2020
• 15. 10.15.5 = (19F2096) – 16″ MBPro Shipping Fork – June 15th 2020
• 14. 10.15.5 = (19F101) – Supplemental Update – June 1st, 2020
• 13. 10.15.5 = (19F96) – May 26, 2020
• 12. 10.15.4 = (19E2269) – 13″MBPro Shipping Fork – May 6th 2020
• 11. 10.15.4 = (19E287) – Supplemental Update – April 8th, 2020
• 10. 10.15.4 = (19E266) – March 24th 2020
• 9. 10.15.3 = (19D2064) – MBAir Shipping Fork March 23rd 2020
• 8. 10.15.3 = (19D76) – January 28th 2020
• 7. 10.15.2 = (19C57) – December 10th 2019
• 6. 10.15.1 = (19B2106) – 16″ MBPro Update Fork – November 13th 2019
• 5. 10.15.1 = (19B2093) – 16″ MBPro Shipping Fork – Nov 13th 2019
• 4. 10.15.1 = (19B88) – October 29th 2019
• 3. 10.15.0 = (19A603) – Supplemental Update Re-Released – Oct 21st 2019
• 2. 10.15.0 = (19A602) – Supplemental Update – October 15th 2019
• 1. 10.15.0 = (19A583) – October 7th 2019

10.15.6 Supplemental Update Info & Download Links

Supplemental Update

The Supplemental Update is only for 10.15.6 users = (19G73, 19G2005, 19G2006 & current version 19G2021)

Download Link – https://support.apple.com/kb/DL2049

Size = 2.8 GB

Product ID = 001-36816

Requirements = 10.15.6

Delta Update

The “Delta” update is smaller in size because it only includes fixes for the previous point release only.

Download Link – support.apple.com/kb/DL2047

Size = 2.97 GB

Product ID = 001-22632

Requirements = 10.15.5

Combo Update

The “Combo” update is for all previous versions of Catalina.

Download Link – support.apple.com/kb/DL2048

Size = 4.78 GB

Product ID = 001-22626

Requirements = 10.15.0, 10.15.1, 10.15.2, 10.15.3, 10.15.4 or 10.15.5

Full Installer.app

Link – Catalina 10.15.6 Mac App Store

Size = 8.75 GB

Product ID = 001-36801

Requirements – 10.15 Catalina Requirements

T2 BridgeOS Update

T2 BridgeOS was updated along with the 10.15.6 Supplemental Update.

Size = 417.7 MB

Product ID = 001-36736

BridgeOS Update Version = 17.16.16610

Previous BridgeOS Update Version = 17.16.16065

If I deployed/cached the old 10.15.6 Installer.app for OS Upgrades, do I need to redeploy?

Do I have to replace my deployable 10.15 Installer.app? – Yes

If you deployed the old version of the 10.15.6 (19G73) Installer, you should update it to the new (19G2021). If you don’t your users will have to install the New Catalina Supplemental Update after installing or upgrading.

Security Content of macOS Catalina 10.15.6 Supplemental Update.

The Supplemental Update does not list any public CVE entries.

Catalina 10.15.6 Supplemental Update