Microsoft Jan 2026 Security Updates: 112 Fixes, Critical Vulnerabilities, and Known Issues
Summary of January 2026 Windows Security updates
Hear’s a breakdown of the January 2026 security updates for various Windows versions, based on the provided text:
Windows 11:
* 25H2: Shares the same vulnerability scope as 24H2. No unique critical vulnerabilities.
* 24H2: Security fixes for remote code execution and privilege elevation, stability improvements, and changes to Secure Boot/virtualization security (KB5074109).
* 23H2 (Enterprise & Education): Receives only cumulative security updates. Security and quality improvements, including secure Boot certificate changes (KB5073455). Known Issue: Systems with Secure Launch enabled may fail to shut down or sleep, potentially restarting instead.Workaround for Shutdown: shutdown /s /t 0 (command prompt). No workaround for sleep mode currently.
Windows 10:
* (Extended Security Updates – ESU only): Security-only update, exclusively for systems enrolled in ESU (KB5073724). General support ended October 2025.
Windows Server:
* 2016, 2019, 2022, 2023, 2025: All supported versions received January security updates.No publicly disclosed critical server vulnerabilities, but multiple critically important vulnerabilities were addressed.
Key Takeaways:
* Secure Boot/Secure Launch Issues: Windows 11 23H2 has a known issue with shutdown/sleep when Secure Launch is enabled.
* ESU Focus: Windows 10 updates are now only for those paying for Extended Security Updates.
* Security is Paramount: All updates prioritize security fixes, addressing remote code execution and privilege elevation vulnerabilities.