Patch tracker / KB5099535
KB5099535: Windows Server 2019 Security Update (July 2026)
KB5099535 is a Critical security update for Windows Server 2019, released 2026-07-14. It closes 261 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-2026-42982, which FIRST.org rates at 64% probability of exploitation in the next 30 days.
Update summary
Fixes 261 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.
- Microsoft is not currently aware of any issues with this update.
KB5099535 is an unusually large Windows 10 1809 and Server 2019 rollup that fixes 260 CVEs, including a Critical flaw rated CVSS 9.9 and at least one CVE already listed in the CISA Known Exploited Vulnerabilities catalog. Any Server 2019 domain controllers, RDS hosts, or 1809 endpoints in your estate are exposed, and the confirmed exploited CVE means attacks are already happening in the wild even though none are ransomware-linked yet.
Do this: Deploy KB5099535 to Server 2019 and Windows 10 1809 systems now, prioritizing internet-facing and domain controller roles because of 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 KB5099535
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5099535
- 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 KB5099535 on 2026-07-29: CVEs fixed 260 to 261.
- 2026-07-29 CVEs fixed 260 to 261
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 KB5099535 is installed
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Known issues, from Microsoft
Quoted from Microsoft's support article for KB5099535 (checked 2026-08-11). Verify against the article before acting.
Microsoft is not currently aware of any issues with this update.
Applies to: Windows 10 Enterprise LTSB 2016 and Windows 10 IoT Enterprise 2016 LTSB
This security update includes fixes and improvements that are a part of the following update:
June 9, 2026—KB5094122 (OS Build 14393.9230)
The following is a summary of the issues that this update addresses. The bold text within the brackets indicates the item or area of the change we are documenting.
[OLE Automation (known issue)] Fixed: Addresses a compatibility issue in OLE Automation (oleaut32.dll) that was introduced by the June 2026 security update. Some applications that use the IDispatch::Invoke method to call COM methods with BYREF parameters that share the same underlying storage might fail. These failures can include parameter marshaling errors or automation call failures. This update corrects how parameter ownership is managed and restores expected application behavior.
[File Explorer (known issue)] Fixed: An issue where the OneDrive shortcut in File Explorer stops working when File Explorer is run with administrative mode.
[Recycle Bin (known issue)] Fixed: This update addresses an issue where the confirmation dialog might display an internal Recycle Bin file name instead of the original file name when permanently deleting a file.
[Secure Boot] This update includes additional high confidence device targeting data, ...
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 · exploitedKB5099445
174 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.