Windows Server August servicing: DFS, PQC and backup reliability

The August 11 Server releases set a new security baseline for Windows Server 2025, 2022, 2019 and 2016.

What changed

Server 2025 improves DFS mapped-drive file handling and restores PQC options for Certificate Authority configuration and enrollment. Server 2019 and 2016 resolve File History backup failures to SMB shares.

Technical details

Server 2025: DFS mapped-drive preview and copy reliability
Server 2025: PQC Certificate Authority and enrollment support
Server 2019 and 2016: File History SMB backup fix
Secure Boot certificate targeting expanded across supported Server releases

Why it matters

The update matters for DFS workloads, certificate authorities, SMB backup jobs and the Server monthly compliance baseline.

Known limitations

WSUS does not display synchronization error details after KB5070881 or later because Microsoft temporarily removed the details for CVE-2025-59287
Microsoft reports no open issue for Server 2019 and Server 2016 August updates

Now check

Use the KB and build table for each Server version
Test DFS, PQC enrollment and SMB backup scenarios in the pilot
Use WSUS and SUP logs rather than the console alone for sync errors