Patch tracker / KB5101649
KB5101649: Windows Server 2019 Security Update (July 2026)
KB5101649 is a Critical security update for Windows Server 2019, released 2026-07-14. It closes 383 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 383 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.
KB5101649 is a Security Update for Windows 11 Version 26H1 on ARM64 and x64 systems, and it addresses CVE-2026-50661, a publicly disclosed BitLocker zero-day. Because this flaw touches BitLocker, machines relying on disk encryption for physical security are the exposed population, and public disclosure means attack details are already circulating. Note the data is provisional since Microsoft has not yet published per-update CVE detail for this July 2026 cycle.
Do this: Deploy KB5101649 to all Windows 11 26H1 ARM64 and x64 devices now, prioritizing any that depend on BitLocker for at-rest data protection.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5101649
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5101649
- 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 KB5101649 on 2026-07-29: CVEs fixed 382 to 383.
- 2026-07-29 CVEs fixed 382 to 383
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 KB5101649 is installed
Elevated PowerShell. No output means it is not installed.
Known issues, from Microsoft
Quoted from Microsoft's support article for KB5101649 (checked 2026-08-11). Verify against the article before acting.
Microsoft is not currently 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 · exploitedKB5099445
174 CVEs · Critical · exploitedKB5099535
261 CVEs · Critical · exploitedKB5099536
389 CVEs · Critical · exploitedKB5099538
312 CVEs · Critical · exploitedKB5099539
314 CVEs · Critical · exploitedKB5099540
326 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.