Windows Server 2022 KB5077800 (OS Build 20348.4650) Out-of-band released
There’s a fresh out-of-band update rolling out for Windows Server 2022 now, KB5077800. It brings cumulative security fixes and other tweaks covering the period since the January 13, 2026, safety patch (KB5073457).
This particular out-of-band release is tackling a specific problem that surfaced after installing that earlier security update from January 13th. Some folks reported being unable to sign in during Remote Desktop sessions because of messed-up authentication affecting several apps.
Importantly for affected systems, this new OOB update only installs the updates it specifically includes, nothing older or newer unless explicitly mentioned by a different cumulative update. This approach bundles up all necessary recent improvements into one download.
It also incorporates KB5074428, which updated the servicing stack itself on build 20348.4640. The servicing stack is what handles installing updates generally. By including this, Microsoft ensures devices can reliably grab and install future Windows fixes as part of ongoing operations.
While it’s a welcome fix for that Remote Desktop issue, though, there's one catch: once you've installed KB5070884 or later, the reporting features in Windows Server Update Services (WSUS) might not show all error details. This seems to be a temporary side effect while they work on patching a major security hole identified as CVE-2025-59287.
January 17, 2026—KB5077800 (OS Build 20348.4650) Out-of-band - Microsoft Support
January 17, 2026—KB5077800 (OS Build 20348.4650) Out-of-band - Microsoft Support
