Note
- Windows Secure Boot certificate expiration
- Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. Microsoft has been updating these certificates on consumer and non-managed business devices for the past months. Devices that haven’t received the newer certificates will continue to start and operate normally, and standard Windows updates will continue to install. We will continue to install the newer certificates via Windows updates in the coming months.
- You can check your PC status on the Windows Security app. If you are an IT administrator, follow the guidance on the Secure Boot Playbook for Windows clients and Windows Server.
Note
- Support for Windows Server 2012 R2 will end in October 2026
- Windows Server 2012 R2 reached the end of support (EOS) on October 10, 2023.
- Extended Security Updates (ESUs) are available for purchase and will continue for three years, renewable on an annual basis, until the final date on October 13, 2026. For information about the procedure to continue receiving security updates, see KB5031043.
- We recommend that you upgrade to a later version of Windows Server. For more information, see Overview of Windows Server upgrades.
Summary
This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) makes sure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.
| Servicing Stack Update (SSU) Guidance for ESU and Azure-Hosted Devices This servicing stack update (SSU) introduces enhanced logic to verify whether a device is hosted in Azure, leveraging an updated certificate chain for validation. To ensure seamless installation of future updates on Azure-hosted devices, it is strongly recommended to install this latest SSU prior to applying any additional updates. Key Requirements for IT Admins Certificate Access Ensure that the device can access the required certificate update domains to successfully download and install certificate updates. For more information, see the following resources: Intermediate Certificate Change An intermediate certificate change will soon be deployed across Azure regions. Before applying updates, verify that your environment is prepared for this change. For guidance, see: ESU Validation Check To confirm whether your machines are eligible for Extended Security Updates (ESU), IT admins should validate the following:
|
|---|
Important Not installing the latest SSU before applying Windows updates might result in the Windows update not being offered until the latest SSU is installed.
How to get this update
Install this update
To install this update, use one of the following release channels.
| Available | Next step |
|---|---|
|
This update is available through Windows Update. It will be downloaded and installed automatically. |
| Prerequisites | There are no prerequisites to apply this update. |
|---|---|
| Restart information | You must restart your computer after you apply this update. |
| Removal information | Servicing stack updates (SSUs) make changes to how updates are installed and cannot be uninstalled from the device. |
| Update replacement information | This update replaces the previously released update KB5066794. |
File Information
The English (United States) version of this software update installs files that have the following attributes. This update might contain files for additional languages.
For all supported x64-based versions
| File name | File version | Date | Time | File size |
|---|---|---|---|---|
| httpai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 57,856 |
| peerdistai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 72,192 |
| PrintAdvancedInstaller.dll | 6.3.9600.22866 | 15-Oct-25 | 21:48 | 102,400 |
| msdtcadvancedinstaller.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 257,536 |
| netfxconfig.dll | 6.3.9600.22866 | 15-Oct-25 | 22:05 | 34,816 |
| ConfigureIEOptionalComponentsAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 84,992 |
| IEFileInstallAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 68,096 |
| servicemodelregai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 115,200 |
| SetIEInstalledDateAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 51,712 |
| ceipfwdai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:30 | 228,352 |
| bcdeditai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:35 | 287,232 |
| appxreg.dll | 6.3.9600.22866 | 15-Oct-25 | 21:58 | 14,848 |
| RegisterIEPKeysAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:31 | 19,968 |
| cmipnpinstall.dll | 6.3.9600.22866 | 15-Oct-25 | 22:03 | 248,832 |
| appserverai.dll | 6.3.9600.22866 | 15-Oct-25 | 22:01 | 146,432 |
| RDWebAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:45 | 140,800 |
| tssdisai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:43 | 156,160 |
| VmHostAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:48 | 123,392 |
| securebootai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:35 | 194,560 |
| winsockai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 69,632 |
| ws2_helper.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 62,976 |
| cleanupai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 33,792 |
| wdscore.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 276,480 |
| CntrtextInstaller.dll | 6.3.9600.22866 | 15-Oct-25 | 21:37 | 153,088 |
| drvstore.dll | 6.3.9600.22866 | 15-Oct-25 | 21:37 | 744,960 |
| dpx.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 345,088 |
| msdelta.dll | 6.3.9600.22866 | 15-Oct-25 | 21:35 | 499,712 |
| mspatcha.dll | 6.3.9600.22866 | 15-Oct-25 | 21:37 | 46,080 |
| cmiv2.dll | 6.3.9600.22866 | 15-Oct-25 | 22:04 | 3,300,352 |
| cmiaisupport.dll | 6.3.9600.22866 | 15-Oct-25 | 21:31 | 3,154,944 |
| cmitrust.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 418,304 |
| WcmTypes.xsd | Not versioned | 15-Oct-25 | 19:23 | 1,047 |
| CbsMsg.dll | 6.3.9600.22866 | 15-Oct-25 | 21:37 | 42,496 |
| CbsCore.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 1,608,704 |
| TiWorker.exe | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 193,024 |
| TiFileFetcher.exe | 6.3.9600.22866 | 15-Oct-25 | 21:30 | 427,520 |
| DrUpdate.dll | 6.3.9600.22866 | 15-Oct-25 | 21:36 | 246,784 |
| wrpint.dll | 6.3.9600.22866 | 15-Oct-25 | 21:30 | 66,048 |
| wcp.dll | 6.3.9600.22866 | 15-Oct-25 | 21:36 | 2,855,424 |
| cmiadapter.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 139,264 |
| smiengine.dll | 6.3.9600.22866 | 15-Oct-25 | 21:25 | 922,624 |
| smipi.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 65,536 |
| poqexec.exe | 6.3.9600.22866 | 15-Oct-25 | 22:17 | 146,432 |
| amd64_installed | Not versioned | 15-Oct-25 | 19:20 | 9 |
| bfsvc.dll | 6.3.9600.22866 | 15-Oct-25 | 21:31 | 85,504 |
| timezoneai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:36 | 101,888 |
| GlobalInstallOrder.xml | Not versioned | 15-Oct-25 | 19:24 | 1,249,919 |
| luainstall.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 53,248 |
| fveupdateai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 61,952 |
| ExtendedSecurityUpdatesAI.dll | 6.3.9600.22866 | 15-Oct-25 | 22:01 | 207,360 |
| mofinstall.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 67,072 |
| esscli.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 388,608 |
| mofd.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 248,320 |
| repdrvfs.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 350,720 |
| fastprox.dll | 6.3.9600.22866 | 15-Oct-25 | 21:33 | 854,016 |
| wbemcomn.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 453,632 |
| wbemcore.dll | 6.3.9600.22866 | 15-Oct-25 | 21:32 | 1,148,928 |
| wmiutils.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 111,104 |
| wbemprox.dll | 6.3.9600.22866 | 15-Oct-25 | 21:34 | 35,840 |
| wmicmiplugin.dll | 6.3.9600.22866 | 15-Oct-25 | 21:30 | 508,928 |
| sppinst.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 769,024 |
| cmifw.dll | 6.3.9600.22866 | 15-Oct-25 | 21:32 | 97,280 |
| FirewallOfflineAPI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:36 | 166,912 |
| NetSetupAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:35 | 65,024 |
| NetSetupApi.dll | 6.3.9600.22866 | 15-Oct-25 | 21:36 | 184,832 |
| httpai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 55,296 |
| peerdistai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 65,024 |
| PrintAdvancedInstaller.dll | 6.3.9600.22866 | 15-Oct-25 | 21:36 | 99,328 |
| msdtcadvancedinstaller.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 215,040 |
| netfxconfig.dll | 6.3.9600.22866 | 15-Oct-25 | 21:48 | 40,448 |
| ConfigureIEOptionalComponentsAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 76,800 |
| IEFileInstallAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:24 | 66,560 |
| servicemodelregai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 96,768 |
| SetIEInstalledDateAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 49,152 |
| ceipfwdai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:25 | 197,632 |
| bcdeditai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:28 | 271,360 |
| appxreg.dll | 6.3.9600.22866 | 15-Oct-25 | 21:43 | 19,968 |
| RegisterIEPKeysAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:26 | 23,040 |
| cmipnpinstall.dll | 6.3.9600.22866 | 15-Oct-25 | 21:46 | 195,072 |
| securebootai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:28 | 176,128 |
| winsockai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 71,680 |
| ws2_helper.dll | 6.3.9600.22866 | 15-Oct-25 | 21:28 | 50,176 |
| cleanupai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 37,376 |
| wdscore.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 208,384 |
| CntrtextInstaller.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 128,000 |
| drvstore.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 610,304 |
| dpx.dll | 6.3.9600.22866 | 15-Oct-25 | 21:24 | 265,216 |
| msdelta.dll | 6.3.9600.22866 | 15-Oct-25 | 21:28 | 398,336 |
| mspatcha.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 36,864 |
| cmiv2.dll | 6.3.9600.22866 | 15-Oct-25 | 21:48 | 2,257,408 |
| cmiaisupport.dll | 6.3.9600.22866 | 15-Oct-25 | 21:26 | 2,162,688 |
| cmitrust.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 286,720 |
| WcmTypes.xsd | Not versioned | 15-Oct-25 | 19:22 | 1,047 |
| CbsMsg.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 41,984 |
| CbsCore.dll | 6.3.9600.22866 | 15-Oct-25 | 21:25 | 1,381,376 |
| TiWorker.exe | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 190,464 |
| TiFileFetcher.exe | 6.3.9600.22866 | 15-Oct-25 | 21:25 | 355,328 |
| DrUpdate.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 202,240 |
| wrpint.dll | 6.3.9600.22866 | 15-Oct-25 | 21:25 | 56,320 |
| wcp.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 2,408,960 |
| cmiadapter.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 121,856 |
| smiengine.dll | 6.3.9600.22866 | 15-Oct-25 | 21:21 | 750,080 |
| smipi.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 59,904 |
| poqexec.exe | 6.3.9600.22866 | 15-Oct-25 | 21:59 | 129,536 |
| x86_installed | Not versioned | 15-Oct-25 | 19:19 | 9 |
| bfsvc.dll | 6.3.9600.22866 | 15-Oct-25 | 21:25 | 81,920 |
| timezoneai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:28 | 86,528 |
| GlobalInstallOrder.xml | Not versioned | 15-Oct-25 | 19:23 | 1,249,919 |
| luainstall.dll | 6.3.9600.22866 | 15-Oct-25 | 21:28 | 43,008 |
| fveupdateai.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 57,344 |
| ExtendedSecurityUpdatesAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:45 | 169,984 |
| mofinstall.dll | 6.3.9600.22866 | 15-Oct-25 | 21:28 | 64,000 |
| esscli.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 293,376 |
| mofd.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 204,800 |
| repdrvfs.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 277,504 |
| fastprox.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 670,208 |
| wbemcomn.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 386,048 |
| wbemcore.dll | 6.3.9600.22866 | 15-Oct-25 | 21:26 | 925,696 |
| wmiutils.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 90,624 |
| wbemprox.dll | 6.3.9600.22866 | 15-Oct-25 | 21:27 | 29,696 |
| wmicmiplugin.dll | 6.3.9600.22866 | 15-Oct-25 | 21:24 | 392,704 |
| sppinst.dll | 6.3.9600.22866 | 15-Oct-25 | 21:24 | 646,656 |
| cmifw.dll | 6.3.9600.22866 | 15-Oct-25 | 21:26 | 80,896 |
| FirewallOfflineAPI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 140,800 |
| NetSetupAI.dll | 6.3.9600.22866 | 15-Oct-25 | 21:28 | 55,296 |
| NetSetupApi.dll | 6.3.9600.22866 | 15-Oct-25 | 21:29 | 124,928 |
References
Servicing Stack Updates (SSU): Frequently Asked Questions
ADV990001 | Latest Servicing Stack Updates
Description of the standard terminology that is used to describe Microsoft software updates