- June 2021 Security Updates release notes
- List of software updates for Microsoft products
- List of the latest Windows Updates and Services Packs
- Security Updates Guide
- Microsoft Update Catalog site
- Our in-depth Windows update guide
- How to install optional updates on Windows 10
- Windows 10 Update History
- Windows 8.1 Update History
- Windows 7 Update History
Microsoft Windows Security Updates June 2021 overview

Microsoft released security updates and non-security updates for all supported client and server versions of Microsoft's Windows operating system as well as other company products. The June 2021 Patch Day is the first that includes Windows 10 version 21H1, the latest Windows 10 feature update that Microsoft released last month.
Our overview links to the security updates that Microsoft released, to support articles and downloads, lists known issues as revealed by Microsoft, and provides system administrators and home users with other relevant information.
Check out the May 2021 Patch overview here in case you want to revisit it.
The Microsoft Windows Security Updates: June 2021
You may download the following Excel spreadsheet to get a list of the security updates released for Microsoft Windows and other company products: Security Updates 2021-06-08-070201pm
Executive Summary
- Windows 10 version 21H1 was released last month. It is rolled out gradually to systems running Windows 10 version 2004 and 20H2 currently.
- All client and server versions of Windows are affected by at least 1 critical security vulnerability.
- Microsoft released updates for other products including Microsoft Office, Microsoft Intune, 3D Viewer, .Net Core & Visual Studio, Windows Defender, Paint 3D and Windows Installer.
Operating System Distribution
- Windows 7 (extended support only): 14 vulnerabilities: 2 critical and 12 important
- Windows MSHTML Platform Remote Code Execution Vulnerability - CVE-2021-33742
- Scripting Engine Memory Corruption Vulnerability -- CVE-2021-31959
- Windows 8.1: 19 vulnerabilities: 2 critical and 12 important
- same critical as Windows 7
- Windows 10 version 1903 and 1909: 24 vulnerabilities: 2 critical and 22 important
- same critical as Windows 7
- Windows 10 version 2004, 20H2 and 21H1 : 25 vulnerabilities, 2 critical and 23 important
- same critical as Windows 7
Windows Server products
- Windows Server 2008 R2 (extended support only): 12 vulnerabilities: 1 critical and 11 important
- Windows MSHTML Platform Remote Code Execution Vulnerability -- CVE-2021-33742
- Windows Server 2012 R2: 19 vulnerabilities: 2 critical and 17 important
- Scripting Engine Memory Corruption Vulnerability -- CVE-2021-31959
- Windows MSHTML Platform Remote Code Execution Vulnerability -- CVE-2021-33742
- Windows Server 2016: 20 vulnerabilities: 2 critical and 18 important.
- same as Windows Server 2012 R2
- Windows Server 2019: 24 vulnerabilities: 2 critical and 22 important
- same as Windows Server 2012 R2
Windows Security Updates
Windows 7 SP1 and Windows Server 2008 R2
Updates and improvements:
- Security updates
- Fixes an issue in the SMB (Server Message Block) protocol which caused frequent crashes with stop error code 0xA on Windows Server 2008 R2 SP1 devices. (Security-only)
Windows 8.1 and Windows Server 2012 R2
Updates and improvements:
- Security updates
Windows 10 version 1909
- Support Page: KB5003635
Updates and improvements:
- Addresses an issue with an inconsistent shutdown during Windows Update that damages the Windows Management Instrumentation (WMI) repository.
- Addresses an issue that might prevent you from signing in to some Microsoft 365 desktop client apps after installing the May 11, 2021 or later update and restarting your device
- Security updates
Windows 10 version 2004, 20H2 and 21H1
- Support Page: KB5003637
Updates and improvements:
- Security updates
Other security updates
2021-06 Cumulative Security Update for Internet Explorer (KB5003636)
2021-06 Security Monthly Quality Rollup for Windows Server 2008 (KB5003661)
2021-06 Security Only Quality Update for Windows Server 2008 (KB5003695)
2021-06 Security Only Quality Update for Windows Embedded 8 Standard and Windows Server 2012 (KB5003696)
2021-06 Security Monthly Quality Rollup for Windows Embedded 8 Standard and Windows Server 2012 (KB5003697)
2021-06 Security Only Quality Update for Windows 8.1 and Windows Server 2012 R2 (KB5003681)
Known Issues
Windows 7 SP1 and Server 2008 R2
- Connections to SQL Server 2005 may fail after installation of the update. Error "Cannot connect to <Server name>" may be displayed.
- Microsoft notes that the behavior is expected and suggests that customers upgrade to a supported version of SQL server.
- Installed update may be reverted.
- Expected behavior if the machine is not supported for ESU.
- Certain operations may fail on Cluster Shared Volumes.
- Either perform the operation from a process with administrator privileges, or from a node that does not have CSV ownership.
Windows 8.1 and Server 2012 R2
- Certain operations may fail on Cluster Shared Volumes.
- Either perform the operation from a process with administrator privileges, or from a node that does not have CSV ownership.
Windows 10 version 1909
- System and user certificates may be lost when the device is updated to a newer version of Windows 10.
- Microsoft suggests to go back to the previous version of Windows, but it is only available up to 30 days after installation of the update.
Windows 10 version 2004, 20H2 and 21H1
- Same system and user certificates issue as version 1909.
- Issue with the Microsoft Japanese Input Method Editor and Japanese Kanji / Furigana characters.
- No workaround at the time of writing. Microsoft is working on a resolution.
- Issues with the performance of games after installing recent updates.
- Is resolved according to Microsoft except for Enterprise-managed devices.
- Issue with Microsoft Edge Legacy being removed but Microsoft Edge (new) not being installed if W10 is installed using custom offline media or ISO images.
- Workaround provided on the support page.
Security advisories and updates
ADV 990001 -- Latest Servicing Stack Updates
Other updates
2021-06 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows Server, version 20H2, Windows 10 Version 20H2, Windows Server, version 2004, Windows 10 Version 2004, Windows 10 Version 1909, and Windows 10 Version 1903 (KB5003254)
2021-06 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version 1909 (KB5003256)
2021-06 Cumulative Update for .NET Framework 3.5 and 4.8 for Microsoft server operating system for ARM64 (KB5003529)
2021-06 Cumulative Update for .NET Framework 4.8 for Windows Server 2016 and Windows 10 Version 1607 (KB5003542)
2021-06 Cumulative Update for Windows 10 Version 1607 (KB5003638)
2021-06 Cumulative Update for Microsoft server operating system version 21H2 for ARM64-basedSystems (KB5003645)
2021-06 Servicing Stack Update for Windows 10 Version 1909 (KB5003710)
2021-06 Servicing Stack Update for Windows Server 2019 and Windows 10 Version 1809 (KB5003711)
2021-06 Cumulative Update for .NET Framework 3.5, 4.7.2 and 4.8 for Windows Server 2019 and Windows 10 Version 1809 (KB5003778)
2021-06 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version 20H2, Windows 10 Version 2004, Windows 10 Version 1909, and Windows 10 Version 1903 (KB5004034)
2021-06 Security and Quality Rollup for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB5003543)
2021-06 Security and Quality Rollup for .NET Framework 4.8 for Windows Embedded 8 Standard and Windows Server 2012 (KB5003544)
2021-06 Security and Quality Rollup for .NET Framework 4.8 for Windows 8.1 and Windows Server 2012 R2 (KB5003545)
2021-06 Security and Quality Rollup for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB5003547)
2021-06 Security and Quality Rollup for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Embedded 8 Standard and Windows Server 2012 (KB5003548)
2021-06 Security and Quality Rollup for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows 8.1 and Windows Server 2012 R2 (KB5003549)
2021-06 Security and Quality Rollup for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB5003779)
2021-06 Security and Quality Rollup for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded 8 Standard and Windows Server 2012 (KB5003780)
2021-06 Security and Quality Rollup for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows 8.1 and Windows Server 2012 R2 (KB5003781)
2021-06 Security and Quality Rollup for .NET Framework 2.0, 3.0, 4.5.2, 4.6 and 4.6.2 for Windows Server 2008 (KB5003782)
2020-05 Security Only Update for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4552951)
2020-05 Security Only Update for .NET Framework 4.5.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4552952)
2020-05 Security Only Update for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4552953)
2020-05 Security Only Update for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4556403)
2020-05 Security Only Update for .NET Framework 2.0, 3.0, 4.5.2, 4.6 for Windows Server 2008 (KB4556406)
2020-07 Security Only Update for .NET Framework 4.5.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4565583)
2020-07 Security Only Update for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4565586)
2020-07 Security Only Update for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4565589)
2020-07 Security Only Update for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4566466)
2020-07 Security Only Update for .NET Framework 2.0, 3.0, 4.5.2, 4.6 for Windows Server 2008 (KB4566469)
2020-08 Security Only Update for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4569733)
2020-08 Security Only Update for .NET Framework 4.6 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4569740)
2020-08 Security Only Update for .NET Framework 4.5.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4569743)
2020-08 Security Only Update for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4570500)
2020-08 Security Only Update for .NET Framework 2.0, 3.0, 4.5.2, 4.6 for Windows Server 2008 (KB4570503)
2020-09 Security Only Update for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4576490)
2020-10 Security and Quality Rollup for .NET Framework 4.5.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4578955)
2020-10 Security and Quality Rollup for .NET Framework 4.6 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4578963)
2020-10 Security and Quality Rollup for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4578977)
2020-10 Security Only Update for .NET Framework 4.5.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4578983)
2020-10 Security Only Update for .NET Framework 4.6 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4578987)
2020-10 Security Only Update for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4578990)
2020-10 Security and Quality Rollup for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4579977)
2020-10 Security and Quality Rollup for .NET Framework 2.0, 3.0, 4.5.2, 4.6 for Windows Server 2008 (KB4579980)
2020-10 Security Only Update for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4580467)
2020-10 Security Only Update for .NET Framework 2.0, 3.0, 4.5.2, 4.6 for Windows Server 2008 (KB4580470)
2021-02 Security and Quality Rollup for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4600944)
2021-02 Security and Quality Rollup for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4600945)
2021-02 Security Only Update for .NET Framework 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4601089)
2021-02 Security Only Update for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Embedded Standard 7, Windows 7, Windows Server 2008 R2, and Windows Server 2008 (KB4601090)
2021-02 Security Only Update for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4602958)
2021-02 Security Only Update for .NET Framework 4.6 for Windows Server 2008 (KB4602961)
2021-02 Security and Quality Rollup for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB4603002)
2021-02 Security and Quality Rollup for .NET Framework 2.0, 3.0, 4.5.2, 4.6 for Windows Server 2008 (KB4603005)
2021-05 Security and Quality Rollup for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Embedded Standard 7, Windows 7, and Windows Server 2008 R2 (KB5001878)
2021-05 Security and Quality Rollup for .NET Framework 2.0, 3.0, 4.5.2, 4.6 for Windows Server 2008 (KB5001882)
Microsoft Office Updates
You find Office update information here.
How to download and install the June 2021 security updates
Security updates are downloaded and installed automatically on most Home systems running Windows. The updates are also released via WSUS and other update management systems, and provided as direct downloads on Microsoft's Update Catalog website.
You can check for updates in the following way on Windows when using Windows Updates:
- Select Start, type Windows Update and load the Windows Update item that is displayed.
- Select check for updates to run a manual check for updates.
Direct update downloads
Below are resource pages with direct download links, if you prefer to download the updates to install them manually.
Windows 7 and Server 2008 R2
- KB5003667 -- 2021-06 Security Monthly Quality Rollup for Windows 7
- KB5003694 -- 2021-06 Security Only Quality Update for Windows 7
Windows 8.1 and Windows Server 2012 R2
- KB5003671 -- 2021-06 Security Monthly Quality Rollup for Windows 8.1
- KB5003681 -- 2021-06 Security Only Quality Update for Windows 8.1
Windows 10 (version 1909)
- KB5003635 -- 2021-06 Cumulative Update for Windows 10 Version 1909
Windows 10 (version 2004)
- KB5003637 -- 2021-06 Cumulative Update for Windows 10 Version 2004
Windows 10 (version 20H2)
- KB5003637 -- 2021-06 Cumulative Update for Windows 10 Version 20H2
Windows 10 (version 21H1)
- KB5003637 -- 2021-06 Cumulative Update for Windows 10 Version 21H1
Additional resources


The 20H2 update for my Windows 10 (June 11, 2021) is causing constant explorer crashes and closures if accessing any applications from the taskbar. The update just before this one stopped me from right clicking on the taskbar. This has been fixed in the 20H2 update, but not without bringing all sorts of other issues to the table (including the explorer/taskbar issue). Microsoft, I’m sick of having to workaround new bugs every single update you force on to my machine!
Which Security update applies to Server 2019? It’s technically v1809 but, well, server-flavored.
The articles shows the vulns for it but no link to get the update.
Running 2004.
I was surprised there was only one update, kb5003637.
There was no Windows Malicious Software Removal Tool update.
I went into Program and Features, under View installed updates, and it also shows a service stack update.
Nice summary as usual. Noticed something…
>Issue with Microsoft Edge Legacy being removed but Microsoft Edge (new) not being installed if W10 is installed using custom offline media or ISO images.<
I used an ISO to go to 21H1 and don't have either edge installed, now I know why.
Maybe if I run another ISO, IE will go POOF! too. No need to press my luck, I suppose.
:)
A weather update feed just showed up today in my taskbar. Is anyone else getting this?
https://i.imgur.com/8uuCjMV.jpg
Slight error:
KB5003165 (May 2021) for Internet Explorer should be KB5003636 (June 2021).
Hi Martin,
Typos and suggested addition under these categories:
Windows Security Updates
————————————
Windows 10 version 1909 *(Reached End-Of-Service on May 11, 2021 Except For Enterprise, Education, and IoT Enterprise)
———————————————————————————————————————————————————————-
Support Page: KB5003637 => SHOULD BE => KB5003635
( where KB5003635 = https://support.microsoft.com/en-us/topic/june-8-2021-kb5003635-os-build-18363-1621-2cc248e5-ca5f-4f51-bce4-004d6863e4cd )
Windows 10 version 2004, 20H2 and 21H1
————————————————————-
Support Page: KB5003173 => SHOULD BE => KB5003637
( where KB5003637 = https://support.microsoft.com/en-us/topic/june-8-2021-kb5003637-os-builds-19041-1052-19042-1052-and-19043-1052-fd782405-7736-478e-b8d0-b08f735f7e54 )
* Suggest additional information for Windows 10 Version 1909
Cheers
Wasn’t May 2021 supposed to be the end of security updates for Windows 1909?! did Microsoft forget LOL
Nice to see I don’t have to deal with the headache of upgrading and fixing things that will get broken in the process, yet…
1909 updates were extended a year for education and enterprise
ohh crap! looks like I have to upgrade…
Martin, IE11 Security Only patching KB5003636 for Win7/8.1/Server 2008R2 and 2012 R2 seems to be missing which is classed as critical according to MSFT.
https://www.catalog.update.microsoft.com/Search.aspx?q=KB5003636
These monthly updates overviews keep proving useful every time again, thank you so much for taking the trouble to list them all here!
This is one of them quality update right here.
got also this one; on a win 7-32 bit home premium –
Security and Quality Rollup for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows 7 SP1 and Windows Server 2008 R2 SP1 (KB5003779)
Like always thanks Martin, for this month’s enlightening update article.
Next, to the news and interests in the taskbar popping up all of a sudden so far so good.
So I updated to Windows 10 version 20H2 OS build 19042.985
Does this fix the issue where news and interest screwed up the system tray? Does Microsoft even know this issue exist?
Nope.
Yeah, screwed mine up too. Uninstalled KB5003637 fixed it for me. Waiting for MS to fix this.
Windows 10 version 2004, 20H2 and 21H1 KB5003637
IE11 CU KB5003636
Check your current KB postings. Some are 2101-05
Thank you, corrected!
No, it’s not. Windows 8.1 IE June update is for May.
In section ‘Windows Security Updates’ / Windows 10 version 2004, 20H2 and 21H1 / Support Page: KB5003173 < is also from May.