Patch tracker / KB5120238
KB5120238: Windows Server 2019 Security Update (August 2026)
KB5120238 is a Critical security update for Windows Server 2019, released 2026-08-11. It closes 174 CVEs with a maximum CVSS of 9.8. At least one of them is actively exploited (CISA KEV), so it is urgent, and Microsoft lists 1 known issue: test it before broad deployment. The most likely of them to be attacked is CVE-2026-68820, which FIRST.org rates at 9% probability of exploitation in the next 30 days.
Before you deploy: Microsoft lists 1 known issue for this update.
Our data comes from Microsoft, CISA and other public sources, and it can be wrong or out of date. If you are unsure, check the linked source before you act, and tell us when we are wrong so we can fix it.
Update summary
Fixes 174 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 9.8 (Critical). EPSS exploit probability up to 8.6%. Among the top half of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Windows 10 Version 1809 for x64-based Systems has shipped since this one: KB5126651 (2026-10-13). For cumulative update families the newer package includes these fixes, so installing that one is usually the shorter path. Verify against your own update rings before you skip this package.
Microsoft documents 1 known issue with this update.
- We are currently not aware of any issues with this update.
Senserva AI Opinion and rich prompt for KB5120238
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5120238
- Released
- 2026-08-11
- Last changed
- 2026-10-30
- Changes tracked
- 11
Senserva began recording day-to-day change history on 2026-07-07, and refreshes it several times a day. Release dates are historical where Microsoft publishes them; revision history is tracked from that date forward, so it does not include changes made before then.
- 2026-08-12 CVEs fixed 181 to 182
- 2026-08-20 CVEs fixed 182 to 183
Recorded by Senserva on the dates shown, from the MSRC release feed. This is what moved and when, which neither the vendor advisory nor NVD publishes.
Check if KB5120238 is installed
Elevated PowerShell. No output means it is not installed.
Known issues, from Microsoft
Quoted from Microsoft's support article for KB5120238 (checked 2026-11-01). Microsoft lists 1 known issue. Verify against the article before acting.
We are currently not aware of any issues with this update.
From the Senserva blog
- Patch Day 2: The August Zero-Day Has an Attacker
August 12, 2026 · Mark Shavlik
CVEs fixed by this update
Sorted exploited-first, then by CVSS. Every CVE links to its Senserva page with the full risk facts, references, and a ready-to-paste AI prompt.
Scope and sources
- Affected products
- Also released in August 2026
KB5120228
204 CVEs · Critical · exploitedKB5120229
184 CVEs · Critical · exploitedKB5120233
204 CVEs · Critical · exploitedKB5120240
160 CVEs · Critical · exploitedKB5120242
184 CVEs · Critical · exploitedKB5120385
136 CVEs · Critical · exploitedKB5120386
131 CVEs · Critical · exploitedKB5120418
162 CVEs · Critical · exploitedThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.