Want a quick overview?: Watch the Windows 11 release note video for this update. |
|---|
Announcements and messages
This section provides key notifications related to this release, including announcements, change logs, and end-of-support notices.
Important
Because of minimal operations during the Western holidays and the upcoming new year, there will be no December 2026 non-security preview update in the second part of the month. Normal monthly servicing for both security and non-security preview updates will resume in January 2027.
Windows Secure Boot certificate expiration
Secure Boot certificate updates remain in progress as Microsoft transitions devices from certificates that began expiring in 2026 to newer certificates. Devices that have not yet received the newer certificates can continue to start and receive standard Windows updates. Microsoft will continue delivering the newer Secure Boot certificates to eligible devices through Windows Update.
Improvements
This update includes improvements from the following previously released updates:
- October 13, 2026—KB5127648 (OS Builds 26300.9711, 26200.9711 and 26100.9711)
- October 26, 2026—KB5134133 (OS Builds 26300.9725, 26200.9725 and 26100.9725) Out-of-band
- October 28, 2026 — KB5127936 (OS Builds 26300.9818 and 26200.9818) Preview
Applies to: Windows 11, versions 26H2 and 25H2, all editions
This security update includes quality improvements. Key changes include:
- [Security updates] This update provides security improvements. For more information about the security vulnerabilities resolved by this update, see the Security Update Guide
- [Secure Boot] This update includes additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Certificate deployment via Windows updates continues across supported PCs and non-managed business devices in the coming months.
- [Audio (known issue)] - Fixed: USB Audio 1.0 devices might fail to start and display error code 10 in Device Manager after installing a recent security update.
- [Printing] Fixed: Adding a printer published in Active Directory through Settings > Bluetooth & devices > Printers & scanners > Add device might fail with error 87, “The parameter is incorrect.” This issue was introduced by the October 2026 update and does not generally affect existing printers or printing.
- [Security] This update improves NTLM security by enabling clients to offer NTLM message signing by default for non-anonymous connections. This change helps reduce exposure to NTLM relay attacks and provides auditing to identify connections that are not using signing. To learn more, see NTLM signing security improvements in Windows.
- [Date and Time] This update adjusts daylight saving time (DST) rules for Cuba for the extended 2026-2027 DST period. Cuba remains on UTC-04:00 and doesn't observe the November 2026 and March 2027 transitions. It returns to UTC-05:00 in November 2027 and resumes its regular seasonal schedule in 2028.
- For the latest DST and time zone guidance, see the Daylight Saving Time & Time Zone Blog.
- [Remote Desktop] This update addresses an issue where Remote Desktop Protocol (RDP) connections might fail on the client due to a certificate mismatch after the October 2026 non-security preview update.
- [Windows PowerShell] This update strengthens security for PowerShell script signing and signature verification by introducing stricter encoding validation. As a result, scripts containing invalid UTF-8 encoding might fail signature validation, even if they were previously accepted. To resolve this issue, review the affected scripts, save them using valid UTF-8 encoding with a byte order mark (BOM), and sign them again. For further guidance, see Encoding Guidance for Signed PowerShell Scripts.
Known issues in this update
Microsoft is not currently aware of any issues with this update.
| Available | Next Step |
|---|---|
|
Open Start
> Settings
> Windows Update > Advanced options > Optional updates. In the Optional updates available area, you will find the link to download and install available updates.Check for optional updates |
File information
A list of the files that are included in this update are provided in a CSV (Comma delimited) (*.csv) file. The file can be opened in a text editor such as Notepad or in Microsoft Excel.
Note The English (United States) version of this software update might contain files for additional languages.
Download the file information for cumulative update KB5132061.
Download the file information for SSU (KB5132688 - version 26100.9971.
Related topics
Windows monthly updates explained
Description of the standard terminology used for Microsoft software updates
Microsoft Store for Business and Education with Configuration Manager
Want a quick overview?: Watch the
> Settings
> Windows Update > Advanced options > Optional updates. In the Optional updates available area, you will find the link to download and install available updates.