January 2026 Delivers Final Windows Security Updates

On January 13, 2026, Microsoft unveiled its initial set of security updates for the year, effectively addressing a staggering total of over 110 security vulnerabilities across various products including the Windows operating system, Microsoft Office suite, Edge browser, Azure components, and numerous other services.

These updates cater to all currently supported versions of Windows. Notably, Windows 10 is limited to security fixes under Microsoft’s Extended Security Updates (ESU) program, while users of Windows 11, specifically versions 24H2 and 25H2, will receive the bulk of these critical updates.

This comprehensive monthly overview serves as an essential resource for both home users and system administrators, summarizing the updates, assessing vulnerability severity, detailing known issues, and providing direct download links for the updates.

January 2026 Microsoft Security Updates

You can download the complete Excel spreadsheet containing all released updates here.

Executive Summary

Microsoft issued approximately 112–114 security updates.
Around 8 vulnerabilities are classified as Critical.
At least one zero-day vulnerability is actively being exploited, as confirmed by Microsoft.
The security enhancements address a range of products including Windows, Office, Edge, and Azure server components.

Known Issues in Windows Clients

Windows 11: versions 23H2, 24H2, 25H2

Windows Server Products with Known Issues

Windows Server 2023
Windows Server 2025

Detailed Product Overview

The following section outlines the affected Windows versions along with their respective vulnerability counts.

Windows 11 Details:

Windows 11 version 24H2

Resolved numerous vulnerabilities.
Includes issues related to remote code execution, privilege escalation, spoofing, and information disclosure.

Windows 11 version 25H2

Encountered the same range of vulnerabilities as version 24H2.
No unique critical vulnerabilities identified for this release.

Windows 11 version 23H2 (Enterprise & Education)

Services through enterprise channels are still available.
Cumulative security updates are provided.

Windows 10 Overview

Windows 10 (ESU only)

This applies solely to machines enrolled in the ESU program.
No feature enhancements will be provided.
General support concluded as of October 2025.

Updates for Windows Server

Windows Server 2016
Windows Server 2019
Windows Server 2022
Windows Server 2023
Windows Server 2025

All supported server releases received updates in January, addressing multiple important vulnerabilities, though no critical issues were publicly disclosed.

Specific Windows Security Updates

Updates for Windows 11 Versions 24H2 and 25H2

View Support Page: KB5074109

Enhancements include:

Multiple fixes for remote code execution and elevation of privilege vulnerabilities.
Improvements to overall system stability and reliability.
Servicing updates regarding Secure Boot and virtualization-based security.

Updates for Windows 11 Version 23H2 (Enterprise & Education)

View Support Page: KB5073455

Enhancements include:

Security fixes and quality improvements.
Updates related to Secure Boot certificates.

Known Issues:

Secure Launch enabled systems may encounter shutdown or sleep mode failures.
Devices may unnecessarily restart instead.

Workaround:

Execute the following command in Command Prompt:

shutdown /s /t 0

As of now, Microsoft has no workaround available for sleep mode issues.

Windows 10 (ESU) Updates

View Support Page: KB5073724

This is a security-only update.
It is exclusively available for systems registered in the ESU.
Includes the removal of outdated modem drivers as part of standard servicing procedures.

Windows Server Updates Overview

Windows Server 2025: KB5073379
Windows Server 2023: KB5073450

These updates focus solely on enhancing security without introducing any new feature changes.

Servicing Stack and Quality Updates

KB5077800: Servicing Stack Update (released January 17, 2026)
- Enhances update installation reliability for older Windows builds.

Microsoft Office Security Updates

Alongside Windows updates, Microsoft released critical security updates for Office and its server components on January 13, 2026.

Updates for Office include:

Excel 2016 — KB5002831
Office 2016 — KB5002826
Word 2016 — KB5002829

SharePoint Server Updates:

SharePoint Server Subscription Edition — KB5002822
SharePoint Server 2019 — KB5002825
SharePoint Server 2016 — KB5002828

Language packs also received the necessary updates.

Post-Update Known Issues

Concerns with Remote Desktop / Azure Virtual Desktop / Windows 365

Following the installation of the January updates, several users reported experiencing:

Failures with credential prompts.
Authentication complications in Azure Virtual Desktop and Windows 365.
These issues primarily impact the new Windows App.

Effective Workarounds:

Utilize the classic Remote Desktop client.
Access the web-based RDP client.

Microsoft is aware of the issue and is actively pursuing resolutions.

Windows 11 23H2 Shutdown and Sleep Concerns

Issue affects systems with Secure Launch enabled.
This configuration interrupts regular shutdown and sleep functionalities.
Full details are available in Windows Release Health documentation.

As of January 18, 2026, Microsoft announced the availability of out-of-band fixes for certain impacted systems.

How to Instantly Install the January 2026 Updates

While security updates are typically distributed automatically, users can opt for manual installation if necessary.

Open the Start menu.
Type Windows Update and select it.
Click on Check for updates.
Select Download & install all.

Best Practice Suggestion:

Prior to installing updates, ensure to create a full system backup, particularly for production environments.