Patch tracker / KB5094042
KB5094042: Windows Server 2019 Security Update (August 2026)
KB5094042 is a Critical security update for Windows Server 2019, released 2026-08-11. It closes 65 CVEs with a maximum CVSS of 9.8. The most likely of them to be attacked is CVE-2026-42990, which FIRST.org rates at 64% probability of exploitation in the next 30 days.
Update summary
Fixes 65 CVEs. Most severe CVSS 9.8 (Critical). EPSS exploit probability up to 23%. Among the top half of tracked Microsoft updates by EPSS exploit probability.
Microsoft documents 3 known issues with this update.
- Microsoft Office applications might fail to open from certain third-party apps
- Deleting from Recycle Bin displays an internal file name
- OneDrive shortcut in File Explorer might not work in administrator mode
KB5094042 is a large July 2026 rollup for Windows 10 version 1809 and Windows Server 2019 that closes 64 CVEs, with the worst rated Critical at CVSS 9.8. No CVE here is on the CISA KEV list or tied to ransomware yet, and the top EPSS is 22 percent, so exploitation is plausible but not confirmed in the wild. The 1809 branch and Server 2019 remain common on domain controllers and long-lived server workloads, which raises the impact of a remotely exploitable 9.8 flaw.
Do this: Schedule KB5094042 deployment now, prioritizing internet-facing and domain controller Server 2019 hosts against the CVSS 9.8 issue.
AI-generated from public data, 2026-07-24. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5094042
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5094042
- Released
- 2026-07-14
- Last changed
- 2026-08-11
- Changes tracked
- 3
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.
Check if KB5094042 is installed
Elevated PowerShell. No output means it is not installed.
Known issues, from Microsoft
Quoted from Microsoft's support article for KB5094042 (checked 2026-08-11). Verify against the article before acting.
Microsoft Office applications might fail to open from certain third-party apps
Symptoms
Microsoft has received reports of an issue in which certain third-party applications might be unable to launch Microsoft Office applications or open documents after installing the Windows updates released on or after June 9, 2026. This issue affects certain third-party applications that use OLE automation to interact with Microsoft Office applications. In some cases, the Office application or document might fail to open without displaying an error message.
Affected Microsoft Office applications might include Word, Excel, PowerPoint, Access, and other Microsoft Office applications when launched from within the affected third-party application.
Reports indicate that this issue may affect applications such as CCH Engagement, Workpaper Manager, dental software (such as Dentrix and Softdent), and Zotero; other similar applications might also be impacted.
Third-party information disclaimer
The third-party products listed are manufactured by companies that are independent of Microsoft. We make no warranty, implied or otherwise, about the performance or reliability of these products.
Resolution
This issue is resolved in Windows updates released on and after July 14, 2026 such as KB5099445 . We recommend you install the latest Windows update for your device as it contains important improvements and ...
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
KB5002882
39 CVEs · Critical · exploitedKB5002883
40 CVEs · Critical · exploitedKB5002891
40 CVEs · Critical · exploitedKB5120228
212 CVEs · Critical · exploitedKB5120229
194 CVEs · Critical · exploitedKB5120233
214 CVEs · Critical · exploitedKB5120238
182 CVEs · Critical · exploitedKB5120240
170 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.