Microsoft released its first set of security updates for the Windows operating system and various products in January 2026, addressing over 110 vulnerabilities. The updates are available for all supported versions of Windows, with Windows 10 receiving fixes only through the Extended Security Updates (ESU) program. Windows 11 versions 24H2 and 25H2 are the main consumer releases benefiting from these updates.
Approximately 112–114 security updates were released, with around 8 rated as Critical. At least one zero-day vulnerability is actively exploited. The updates include security fixes for Windows, Office, Edge, Azure, and server components.
Windows 11 versions 23H2, 24H2, and 25H2, as well as Windows Server 2023 and 2025, have known issues. Windows 11 version 24H2 and 25H2 received security fixes for multiple vulnerabilities, while version 23H2 continues to receive support through enterprise servicing channels. Windows 10 updates are limited to ESU-enrolled systems, with general support ending in October 2025.
Windows Server 2016, 2019, 2022, 2023, and 2025 received January security updates, addressing important vulnerabilities without disclosing any critical ones. Microsoft also released updates for Office products and SharePoint Server components.
Known issues after the January updates include credential prompt failures and authentication issues in Azure Virtual Desktop and Windows 365, particularly affecting the new Windows App. Workarounds involve using the classic Remote Desktop client or the web-based RDP client. Additionally, devices with Secure Launch enabled may experience shutdown and sleep mode failures.
Microsoft has provided out-of-band fixes for certain affected systems as of January 18, 2026. Users can manually install updates through the Windows Update feature, and it is recommended to create a full system backup before proceeding with updates.