A critical shield has been deployed for Windows 10 users. Microsoft has quietly released update KB5073724, a focused security reinforcement arriving in early 2026. This isn't about flashy new features; it's about fortifying the system against emerging digital threats.
The update specifically targets those still relying on Windows 10 21H2, the LTSC 2021 edition, or those actively participating in the Extended Security Updates (ESU) program. For these users, maintaining a secure operating environment is paramount, and this patch delivers precisely that.
KB5073724 doesn’t introduce any visible changes to the user experience. Instead, it operates behind the scenes, meticulously addressing vulnerabilities discovered within the core of the Windows 10 operating system. It’s a silent guardian, working to protect against potential exploits.
This update consolidates security improvements previously released in December 2025 through updates KB5071546 and KB5074976. It’s a streamlined approach, ensuring a consistent and robust security posture for those who need it most.
A significant change involves the removal of specific modem drivers – agrsm64.sys, agrsm.sys, smserl64.sys, and smserial.sys. Devices relying on these drivers will unfortunately lose functionality. This is a crucial detail for users with older modem hardware.
The update also enhances Secure Boot capabilities. Windows is now equipped to automatically receive updated certificates, bolstering the system’s defenses against malware that attempts to tamper with the boot process. This rollout is carefully phased to ensure stability and security.
A core component, WinSqlite3.dll, has been updated, resolving a potential vulnerability flagged by some security software. This addresses concerns about the integrity of a fundamental system library, reinforcing overall security.
Currently, Microsoft reports no known issues affecting typical users during the installation of KB5073724. However, potential compatibility concerns have been identified with Azure Virtual Desktop and Windows 365 environments.
For most users, the update will arrive automatically through the standard Patch Tuesday release cycle. Windows will handle the installation seamlessly in the background, requiring no direct intervention. It’s a quiet, efficient process.
If you prefer, you can proactively check for updates within the Windows Update settings. Alternatively, the update is available for direct download from the Microsoft Update Catalog, offering a manual installation option.
