This report covers the Windows Server 2022 LTSC (Long-Term Servicing Channel) Version 21H2 update released in December 2025 Release Summary Update ID: Release Date: December 9, 2025 20348.4529 Architecture: English (US/International) Servicing Channel:
LTSC (Mainstream support until October 2026; Extended until October 2031) Microsoft Support Key Update Components Security Fixes
: Addressed 57 newly disclosed vulnerabilities across Microsoft products, including high-severity flaws in Windows and Office. Critical Patch CVE-2025-62221
, an elevation of privilege vulnerability in the Windows Cloud Files Mini Filter Driver that could allow an attacker to gain SYSTEM access. Cumulative Improvements windows server 2022 ltsc 21h2 x64 english decem updated
: Includes all security fixes and performance improvements from previous months, such as the November Combined SSU
: The Latest Cumulative Update (LCU) is bundled with the Servicing Stack Update (SSU) to ensure the system can reliably receive and install future patches. Arctic Wolf Core Platform Features Windows Server 2022 update history - Microsoft Support
Note: Since “December updated” typically refers to the latest monthly rollup, I’ve assumed December 2025 for timeliness, but you can adjust the year as needed. This report covers the Windows Server 2022 LTSC
In the ever-evolving landscape of enterprise IT, stability and security are not just goals—they are requirements. Microsoft’s server operating systems form the backbone of countless business networks, cloud infrastructures, and data centers worldwide. Among these, Windows Server 2022 LTSC 21H2 x64 English DecEM Updated stands as a critical milestone for system administrators, managed service providers (MSPs), and IT professionals managing English-language environments.
But what exactly does this specific version designation mean? Why is the December (DecEM) update so crucial? And how can you leverage this release to fortify your infrastructure? Windows Server 2022 LTSC 21H2 x64 English DecEM
This article dives deep into every aspect of this release—from its core architecture (LTSC, 21H2, x64) to its security patches, performance improvements, deployment best practices, and known issues. By the end, you’ll have a complete roadmap for integrating this version into your enterprise ecosystem.
Previously, TLS 1.3 was available but required registry configuration. The December cumulative update made it configurable via Schannel and enabled it for IIS and RDS by default (if the client supports it).
Refers to the base language pack (en-US). While you can add language packs later, the “English” designation ensures: