Patch tracker / KB5099445
KB5099445: Windows Server 2019 Security Update (July 2026)
KB5099445 is a Critical security update for Windows Server 2019, released 2026-07-14. It closes 174 CVEs with a maximum CVSS of 9.9. At least one of them is actively exploited (CISA KEV), so this is a deploy-first update. The most likely of them to be attacked is CVE-2026-34346, which FIRST.org rates at 64% probability of exploitation in the next 30 days.
Update summary
Fixes 174 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 9.9 (Critical). EPSS exploit probability up to 64%. Among the top 25% of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Windows 10 Version 1809 for 32-bit Systems has shipped since this one: KB5094041 (2026-08-11). 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.
KB5099445 is an unusually large July 2026 rollup for Windows 10 1809 and Windows Server 2019, patching 173 CVEs including one rated Critical at CVSS 9.9 and at least one already listed in the CISA Known Exploited Vulnerabilities catalog. The confirmed exploitation plus the large surface means both client and Server 2019 estates are exposed, though none of the flaws are currently tied to ransomware campaigns. The 11% peak EPSS is modest, but the KEV entry makes real-world attack activity a present concern rather than a theoretical one.
Do this: Deploy KB5099445 to your Windows 10 1809 and Server 2019 systems now, prioritizing the internet-facing Server 2019 hosts given the KEV-listed CVE.
AI-generated from public data, 2026-07-25. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5099445
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5099445
- Released
- 2026-07-14
- Last changed
- 2026-07-29
- 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.
Microsoft revised KB5099445 on 2026-07-29: CVEs fixed 173 to 174.
- 2026-07-29 CVEs fixed 173 to 174
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 KB5099445 is installed
Elevated PowerShell. No output means it is not installed.
Known issues, from Microsoft
Quoted from Microsoft's support article for KB5099445 (checked 2026-08-11). Verify against the article before acting.
We are currently not aware of any issues with this update.
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 July 2026
KB5099444
185 CVEs · Critical · exploitedKB5099535
261 CVEs · Critical · exploitedKB5099536
389 CVEs · Critical · exploitedKB5099538
312 CVEs · Critical · exploitedKB5099539
314 CVEs · Critical · exploitedKB5099540
326 CVEs · Critical · exploitedKB5101649
383 CVEs · Critical · exploitedKB5101650
380 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.