Security News Microsoft September 2026 Patch Tuesday fixes 966 flaws, 2 zero-days

[lokamoka820]

Since Tuesday's update, my computers have been incorrectly reporting that Windows Defender is disabled a few minutes after startup.

Although I haven't installed any updates yet (I pause updates and install them monthly), I've been having the same problem as you since yesterday.

 

[I Walk MY Way]

Me too. Since Tuesday's update, my computers have been correctly reporting that Windows Defender is disabled
one of my PCs keeps reporting Windows Defender is disabled, and it is it has macfee on it.

 

[stonjean633]

View attachment 299893

Reinstall actually worked Updates worked. Sadly no videos this time of me blowing up my laptop with a shotgun

Only problem is Intel GPU drivers reinstall every boot through WU. Latest release never installs correctly even with Hard_Configurator reset to default and uninstalled.



@Bot any help? Anyone else?

You can disable driver update in device installation settings somewhere in device manager.

 

[Jonny Quest]

My Microsoft Surface 5 laptop is giving me the WD/Windows Security notice, but not on my HP Envy laptop? Got one just now.

 

[Divine_Barakah]

My Microsoft Surface 5 laptop is giving me the WD/Windows Security notice, but not on my HP Envy laptop? Got one just now.

View attachment 299902

See my 2026 Config. I encountered the exact issue and fixed it by running some commands in PS.

 

[Divine_Barakah]

For those experiencing issues with MD showing as disabled, you need to run these commands in elevated PS.

Post in thread 'Divine_Barakah's PC Security Config 2026'

Advanced Plus Security Post in thread 'Divine_Barakah's PC Security Config 2026'

Aug 22, 2026

Other users reporting the same issue on Reddit

https://www.reddit.com/r/windowsinsiders/s/3OMUp5IehV

https://www.reddit.com/r/pchelp/s/vXwWOTt06g

https://www.reddit.com/r/Intune/s/wY0Yk9MbZQ

Running these commands in Powershell fixed the issue for me

# 1. Set update channels to stable staged ring
Set-MpPreference -EngineUpdatesChannel Staged
Set-MpPreference -PlatformUpdatesChannel Staged
Set-MpPreference -DefinitionUpdatesChannel Staged

# 2. Reset the Defender platform to OS baseline
& "C:\Program Files\Windows Defender\MpCmdRun.exe" -ResetPlatform

# 3...

• Divine_Barakah

MS deliberately sets the beta update channel on some devices.

 

[Victor M]

966 flaws fixed - putting MDASH and Mythos to use, putting more staff on it, good job MS !

Next: find those staffers who coded the flaws and send them to secure coding training, so they don't keep repeating mistakes. At least inform them of the flaw found so they can learn from it.

 

[Jonny Quest]

For those experiencing issues with MD showing as disabled, you need to run these commands in elevated PS.

Post in thread 'Divine_Barakah's PC Security Config 2026'

Advanced Plus Security Post in thread 'Divine_Barakah's PC Security Config 2026'

Aug 22, 2026

Other users reporting the same issue on Reddit

https://www.reddit.com/r/windowsinsiders/s/3OMUp5IehV

https://www.reddit.com/r/pchelp/s/vXwWOTt06g

https://www.reddit.com/r/Intune/s/wY0Yk9MbZQ

Running these commands in Powershell fixed the issue for me

# 1. Set update channels to stable staged ring
Set-MpPreference -EngineUpdatesChannel Staged
Set-MpPreference -PlatformUpdatesChannel Staged
Set-MpPreference -DefinitionUpdatesChannel Staged

# 2. Reset the Defender platform to OS baseline
& "C:\Program Files\Windows Defender\MpCmdRun.exe" -ResetPlatform

# 3...

• Divine_Barakah

MS deliberately sets the beta update channel on some devices.

Thanks, but is it better to wait for Microsoft to come up with a patch, so this helpful aid doesn't break anything when the patch come out?
I just got a notification on this HP laptop, so now it's happening on both. I'll just disable the notifications for the time being.

 

[Divine_Barakah]

Thanks, but is it better to wait for Microsoft to come up with a patch, so this helpful aid doesn't break anything when the patch come out?
I just got a notification on this HP laptop, so now it's happening on both. I'll just disable the notifications for the time being.

No need to wait for MS. The commands just change the update channel to "staged" and they reset the security platform to its original state then updates MD using the new update channel.

 

[lokamoka820]

I just got a notification on this HP laptop, so now it's happening on both. I'll just disable the notifications for the time being.

Does it happen to you often? For me, it only happens when I restart my laptop.

 

[Jonny Quest]

Does it happen to you often? For me, it only happens when I restart my laptop.

On the Surface 5, it would happen about 2-5 minutes after a restart, then about 1-2 more times while I was using it, about 3-4 hours time.
On this HP laptop, it happened after about 3 hours in using it.

 

[Divine_Barakah]

On the Surface 5, it would happen about 2-5 minutes after a restart, then about 1-2 more times while I was using it, about 3-4 hours time.
On this HP laptop, it happened after about 3 hours in using it.

If you check realtime protection in PS, you will find that is running. The issue is purely cosmetic. It is just a sync mismatch at system startup. In my case I received the notification 5 mins after startup.

If you change the update channel to "staged" it is less likely to experience such issues in the future.

 

[Jonny Quest]

If you check realtime protection in PS, you will find that is running. The issue is purely cosmetic. It is just a sync mismatch at system startup. In my case I received the notification 5 mins after startup.

If you change the update channel to "staged" it is less likely to experience such issues in the future.

Thanks, I appreciate the help and concern, and it looks good, is running. But, I'll just wait for the patch to come out

 

[RoboMan]

Broke my PC lol.

Killed wifi and bluetooth drivers, tried a system restore and it got stuck mid process. Had to force reboot and nothing worked after that. Had to use my backup system image hehe.

 

[Marko :)]

Everything works fine on my end. Including Defender.

 

[oldschool]

Everything works fine on my end. Including Defender.

Same here.

 

[oldschool]

No need to wait for MS.

Agreed. Your commands are simply a little housekeeping.

The commands just change the update channel to "staged" and they reset the security platform to its original state then updates MD using the new update channel.

It's clearly a fluke of a bug introduced around a regular WS update. I never had an issue using the Beta channel myself. Go figure ... Windows Security is occasionally buggy, so it seems.

 

[Divine_Barakah]

Agreed. Your commands are simply a little housekeeping.

It's clearly a fluke of a bug introduced around a regular WS update. I never had an issue using the Beta channel myself. Go figure ... Windows Security is occasionally buggy, so it seems.

The issue was caused by the latest security platform update. I was one of the first to experience the issue. At first I thought there was sth wrong in my config, but taking a look at Reddit showed that many users have reported the same issue. The only thing they had in common is the security platform update. Resetting it, and changing the update channel to staged fixed it for me on two devices.

Edit:

You don't need to be using MD to experience the issue. You can run a 3rd party security solution and still experience the issue.

 

[Divine_Barakah]

Everything works fine on my end. Including Defender.

Same here.

That is expected as MS is being selective on what devices to use the beta update channel. I never enabled it myself, but when I checked the current update channel, it was set to Beta and I had to change it to Staged.

 

[Divine_Barakah]

Thanks, I appreciate the help and concern, and it looks good, is running. But, I'll just wait for the patch to come out


View attachment 299934

Yes I told you it is a cosmetic issue. But honestly I was worried that sth was wrong in my config. But when I checked real time protection status in PS I realised it was just a glitch that happens only once on system startup.

But to avoid similar future issues, I changed the update channel to Staged. If MS ever issues a corrupted update, you won't be one of the first victims.