Patch tracker / KB5101649
KB5101649: Windows 11 version 26H1 Security Update (July 2026)
KB5101649 is a Critical security update for Windows 11 version 26H1, released 2026-07-14. It closes 377 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-2026-32202, which FIRST.org rates at 71% probability of exploitation in the next 30 days.
Our data comes from Microsoft, CISA and other public sources, and it can be wrong or out of date.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 377 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 9.9 (Critical). EPSS exploit probability up to 71%. Among the top 25% of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Windows 11 version 26H1 for x64-based Systems has shipped since this one: KB5127646 (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.
We checked Microsoft's support article for KB5101649 on 2026-11-03 and it lists no known issues. Read the article before broad deployment; Microsoft adds issues as reports come in, and we re-check on every refresh.
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
- 2026-10-28
- 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.
Microsoft revised KB5101649 on 2026-10-28: CVEs fixed 382 to 377.
- 2026-07-29 CVEs fixed 382 to 383
- 2026-10-13 CVEs fixed 383 to 384
- 2026-10-25 CVEs fixed 384 to 382
- 2026-10-28 CVEs fixed 382 to 377
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.
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
182 CVEs · Critical · exploitedKB5099445
171 CVEs · Critical · exploitedKB5099535
258 CVEs · Critical · exploitedKB5099536
383 CVEs · Critical · exploitedKB5099538
308 CVEs · Critical · exploitedKB5099539
310 CVEs · Critical · exploitedKB5099540
322 CVEs · Critical · exploitedKB5101650
374 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.