Windows 11. januar 2026-opdatering: Kritiske sikkerhedsrettelser og hvad du skal vide

January 2026 has brought significant changes to the Windows ecosystem, with Microsoft releasing critical security updates, addressing widespread bugs, and rolling out its largest Patch Tuesday in years. If you’re running Windows 11 or considering upgrading your license, understanding these latest developments is crucial for maintaining security, stability, and optimal performance on your PC.

In this comprehensive guide, we’ll break down everything you need to know about the Windows 11 January 2026 updates, including the 114 security vulnerabilities patched, confirmed bugs affecting users, new features rolling out, and essential recommendations for keeping your system secure.

January 2026 Patch Tuesday: 114 Security Fixes You Can’t Ignore

Microsoft’s January 2026 Patch Tuesday represents one of the most substantial security updates in recent history, addressing 114 vulnerabilities across Windows operating systems and related software. This marks the third-largest January Patch Tuesday on record, following January 2025 and January 2022.

Breaking Down the Security Vulnerabilities

The January 2026 security update includes eight critical-severity vulnerabilities and 106 important-severity issues. The vulnerabilities are categorized as follows:

The Actively Exploited Zero-Day: CVE-2026-20805

The most critical concern in this update is CVE-2026-20805, an information disclosure vulnerability in the Desktop Window Manager that Microsoft confirms is being actively exploited in the wild. Despite receiving a moderate CVSS score of 5.5, this flaw is particularly dangerous because attackers are already using it to compromise systems.

Desktop Window Manager handles how windows are organized on your screen, making this vulnerability especially concerning. Security researchers note that flaws like this are commonly leveraged to undermine Address Space Layout Randomization, a core security control that protects against buffer overflows and memory manipulation exploits.

Action Required: Install the January 2026 security updates immediately to protect your system from this active threat. Users running Windows 11 25H2, 24H2, or 23H2 should prioritize this update.

Secure Boot Certificate Expiration: CVE-2026-21265

Another significant vulnerability addresses a security feature bypass affecting Secure Boot Certificate Expiration. This flaw could allow attackers to undermine the crucial security mechanism that ensures firmware modules come from trusted sources and prevents malware from running during the boot process.

Microsoft announced in November 2025 that it will expire three Windows Secure Boot certificates issued in 2011, with deadlines approaching in June and October 2026. Users must update to the 2023 certificate counterparts to maintain Secure Boot protection. The affected certificates include:

• Microsoft Corporation KEK CA 2011 (expires June 2026) → Microsoft Corporation KEK 2K CA 2023
• Microsoft Windows Production PCA 2011 (expires October 2026) → Windows UEFI CA 2023
• Microsoft UEFI CA 2011 (expires June 2026) → Microsoft UEFI CA 2023

These certificates are used by most Windows devices for secure boot verification. Failing to update before the expiration dates could result in boot failures or security vulnerabilities.

Windows Virtualization-Based Security Vulnerability

CVE-2026-20876 represents a critical privilege escalation flaw in Windows Virtualization-Based Security Enclave. With a CVSS score of 6.7, this vulnerability enables attackers to obtain Virtual Trust Level 2 privileges, potentially allowing them to subvert security controls, establish deep persistence, and evade detection.

For enterprise users and security-conscious individuals relying on VBS for enhanced protection, applying this patch is non-negotiable.

Confirmed Issues with Windows 11 January 2026 Update

While the security patches are critical, Microsoft has confirmed several bugs affecting users who installed the January 2026 updates. Understanding these issues helps you decide whether to install immediately or wait for Microsoft’s fixes.

Remote Desktop Connection Failures

Microsoft officially acknowledged that the Windows 11 January 2026 Update (KB5074109) causes Remote Desktop connections to fail when using the Windows app (formerly Remote Desktop) with Azure Virtual Desktop and Windows 365. Users affected by this issue cannot sign in or access desktops through Remote Desktop functionality.

Status: Microsoft released an out-of-band fix on January 17, 2026 (KB5077744) to address this issue. Enterprise users experiencing Remote Desktop problems should install this emergency patch.

Shutdown Issues on Windows 11 23H2

Users running Windows 11 version 23H2 with specific features enabled reported that the “Shut down” function stops working after installing the January update. This rare but critical bug affects older PCs and prevents proper system shutdown.

Status: Resolved with the January 17, 2026 out-of-band update (KB5077744). Microsoft implemented a Known Issue Rollback to temporarily disable the change causing this problem while working on a permanent solution.

Outlook Freezing and Performance Issues

Widespread reports indicate that Microsoft Outlook freezes or experiences performance degradation after the January 2026 update. This issue affects users across Windows 11 25H2, 24H2, and 23H2 versions.

Status: Microsoft has confirmed the bug and is actively investigating. No official fix has been released yet, though some users report that reinstalling Outlook or running it in Safe Mode provides temporary relief.

Additional Unacknowledged Issues

Users have reported several other problems that Microsoft has not officially recognized:

• Black Screen Delay: Some users experience a black screen for several seconds or minutes before the cursor appears and the desktop loads
• Desktop Background Reset: The desktop wallpaper resets to black, requiring users to manually set up their wallpaper or Spotlight again
• File Explorer desktop.ini Bug: The desktop.ini feature no longer works, preventing users from setting custom folder names

If you encounter these issues, Microsoft recommends uninstalling the update until permanent fixes are released.

What’s New: Features Rolling Out in January 2026

While the January 2026 Patch Tuesday focuses primarily on security fixes, Microsoft continues to roll out new features to Windows 11 users through gradual deployment. Here’s what you might see after installing the latest updates:

New Start Menu with Categories Layout

Windows 11 users are waking up to a redesigned Start menu that automatically scales and groups apps into categories. This massive overhaul changes how applications are organized, though not everyone appreciates the unsolicited change. The new layout aims to make finding apps easier through automatic categorization, but users who prefer manual organization may find it disruptive.

Share with Copilot on the Taskbar

Microsoft is expanding the “Share with Copilot” feature that allows users to share the screen of open applications directly with Copilot for AI-powered assistance. When hovering over apps on the taskbar, users now see a toggle to immediately begin sharing their app’s screen with Copilot for questions and guidance.

This feature leverages a new Windows API originally designed for communication apps like Teams, but Microsoft has extended it to work with chatbots. While currently limited to Copilot, the API could theoretically support other AI assistants like ChatGPT if granted Microsoft approval.

Colorful Battery Icons

Windows 11 now displays more vibrant, colorful battery icons on the taskbar, providing better visual feedback about battery status. This aesthetic improvement makes it easier to quickly assess battery levels at a glance.

Advanced Settings Page

The Settings app includes a newly renamed “Advanced Settings” page (previously called “For Developers”). This change makes advanced configuration options more accessible to power users without the “developer” label that might deter some from exploring these features.

Windows 11 Update KB Numbers: Which Version Are You Running?

Understanding which update applies to your Windows 11 version helps ensure you’re installing the correct patches. Here’s a breakdown of the January 2026 updates:

Windows Server 2025 Gets New KB Identifier

Microsoft made a significant change in January 2026 by moving Windows Server 2025 to a new KB identifier system. The update (KB5073379) bumps the OS to Build 26100.32230, and going forward, Windows Server 2025 will have KB numbers that no longer match Windows 11 consumer editions.

According to Microsoft, this change improves clarity for administrators managing enterprise environments. Installation and management processes remain identical, but the unique KB numbers help differentiate server updates from client updates.

Other Windows Server versions received the following updates:

• Windows Server 2023: KB5073450 (Build 25398.2092)
• Windows Server 2022: KB5073457 (Build 20348.4648)

Driver Removal: Agere Modem Drivers Eliminated

Microsoft removed Agere Soft Modem drivers (agrsm64.sys and agrsm.sys) that were shipped natively with Windows. These third-party drivers contained a two-year-old local privilege escalation flaw (CVE-2023-31096) that could allow attackers to gain SYSTEM permissions.

This follows Microsoft’s October 2025 removal of another Agere Modem driver (ltmdm64.sys) after in-the-wild exploitation of a privilege escalation vulnerability. Modern alternatives for networking are already included in Windows, making these legacy drivers unnecessary and removing them enhances system security.

Should You Install the January 2026 Update?

The decision to install the January 2026 updates depends on your specific situation and risk tolerance. Here’s our recommendation based on different user scenarios:

Install Immediately If:

• You handle sensitive data or operate in a business environment where security is paramount
• Your system is exposed to the internet regularly and could be targeted by the actively exploited CVE-2026-20805 vulnerability
• You’re running enterprise or managed IT environments requiring up-to-date security patches
• You don’t rely heavily on Remote Desktop, Outlook, or the specific features affected by known bugs

Consider Waiting If:

• You depend on Microsoft Outlook for daily work and cannot afford freezing or performance issues
• Remote Desktop is essential to your workflow and you use Azure Virtual Desktop or Windows 365
• You’ve experienced issues with previous Windows updates and prefer to wait for bug fixes
• You’re running Windows 11 23H2 and frequently use the shutdown function

Best Practice Approach

For most users, we recommend installing the January 2026 security updates to protect against the actively exploited vulnerability and the 113 other security flaws. The confirmed bugs affect specific scenarios, and Microsoft has already released out-of-band fixes for the most critical issues.

Before installing, create a system restore point or full backup. This allows you to roll back if you encounter problems. After installation, test critical functionality including Remote Desktop, Outlook, and any business-critical applications.

Looking Ahead: Windows 11 25H2 and Beyond

Microsoft continues to push Windows 11 25H2 as the primary consumer release, with widespread rollout beginning in January 2026. Version 25H2 is an enablement package based on the same platform as 24H2, meaning upgrades are smooth and quick for most users.

Key developments for 2026 include:

• Windows 11 24H2 Support Ends October 2026: Microsoft will stop releasing security updates for version 24H2 on October 4, 2026, forcing users to upgrade to 25H2
• Windows 11 26H1 Coming Spring 2026: A new version targeting ARM-based devices with Snapdragon X2 processors will arrive in spring, though existing Intel/AMD PCs will remain on 25H2
• Dark Mode Improvements: Microsoft is expanding dark mode to more system dialogs, progress bars, and legacy UI elements throughout 2026
• Taskbar Agenda View Returning: The calendar flyout will finally show upcoming events and meetings, a feature Windows 10 had but was removed in Windows 11

Optimize Your Windows 11 Experience with Genuine Licensing

Staying secure with the latest Windows 11 updates requires a genuine, properly licensed copy of the operating system. Without an authentic license, you won’t receive critical security patches like the January 2026 update, leaving your system vulnerable to the 114 exploits Microsoft just patched.

På SoftwareLicense4U.com, we provide genuine Windows 11 licenses at competitive prices, ensuring you have access to all security updates, feature enhancements, and Microsoft support. Whether you’re running Windows 11 Home, Pro, or need to upgrade from an older version, we have licensing solutions that fit your needs and budget.

Why Choose Genuine Windows 11 Licenses?

• Complete Security Update Access: Receive all critical patches including the January 2026 security update addressing 114 vulnerabilities
• Feature Updates: Get access to new features like the redesigned Start menu, Copilot integration, and upcoming improvements
• Microsoft Support: Access official technical support when you encounter issues or need assistance
• Legal Compliance: Ensure your software usage complies with Microsoft’s terms of service and licensing agreements
• Long-Term Viability: Windows 11 receives support well into the 2030s, making it a future-proof investment

Frequently Asked Questions About the January 2026 Update

How do I install the Windows 11 January 2026 update?

Open Settings, navigate to Windows Update, and click “Check for updates.” The January 2026 security update will download and install automatically. Alternatively, you can download the specific KB update from the Microsoft Update Catalog for offline installation.

What should I do if the update causes problems?

If you experience issues after installing the January 2026 update, you can uninstall it through Settings > Windows Update > Update history > Uninstall updates. Microsoft also released an out-of-band fix (KB5077744) on January 17, 2026 that addresses the most critical bugs.

Will the update affect my programs or files?

Security updates typically don’t affect programs or personal files. However, some users have reported issues with specific applications like Outlook. It’s always recommended to back up important data before installing major updates.

How large is the January 2026 update download?

The download size varies by Windows version but typically ranges from 400MB to 800MB for the cumulative update. The actual installation size may be smaller due to compression and differential updates.

Can I delay the January 2026 update?

Windows 11 Home users can pause updates for up to 5 weeks through Windows Update settings. Pro, Enterprise, and Education editions can defer updates for longer periods. However, given the actively exploited vulnerability, delaying this security update is not recommended.

Conclusion: Security Should Be Your Priority

The Windows 11 January 2026 update represents a critical security milestone with 114 vulnerabilities patched, including one actively exploited in the wild. While confirmed bugs affecting Remote Desktop, Outlook, and other features may cause temporary inconvenience, the security benefits far outweigh the risks of remaining unpatched.

Microsoft has demonstrated responsiveness by releasing out-of-band fixes for the most critical issues within days of the Patch Tuesday release. For users experiencing bugs, solutions are already available or coming soon.

Maintaining a genuine Windows 11 license ensures you continue receiving these essential security updates throughout the operating system’s lifecycle. At SoftwareLicense4U.com, we’re committed to providing authentic Microsoft licenses that keep you protected, productive, and compliant.

Ready to secure your Windows 11 experience? Visit SoftwareLicense4U.com to explore our Windows 11 licensing options and ensure your system stays protected with the latest security updates. Our customer support team is available to answer questions and help you choose the right license for your needs.