Windows Server 2019 · KB5122876 · Build 17763.9245

What changed

Microsoft published the 2026-09-08 security baseline for Windows Server 2019 with KB5122876 and build 17763.9245.

Technical details

• KB5122876 security update for Windows Server 2019
• OS build 17763.9245

Why it matters

The current Microsoft KB and OS build are the baseline for deployment rings, compliance and servicing reports.

Known limitations

• Review the linked Microsoft KB for current known issues, safeguards and resolved issues.

Now check

• Validate KB5122876 and build 17763.9245 in the pilot ring
• Review the Microsoft KB known-issue section
• Confirm servicing stack and update media prerequisites