CVE-2026-56644: Microsoft Windows Kernel privilege escalation via use after free

CVE-2026-56644 · Severity: high · CVSS 7.8 · Published 2026-07-14

A security vulnerability has been identified in the Windows Kernel, the core component of the Microsoft Windows operating system. This flaw allows a user who already has basic access to a computer to gain full administrative control over the system. An attacker could use this elevated access to view sensitive data, install malicious software, or disrupt business operations.

Technologies: Microsoft Windows 10 Version 1607, Microsoft Windows 10 Version 1809, Microsoft Windows 10 Version 21H2, Microsoft Windows 10 Version 22H2, Microsoft Windows 11 Version 24H2, Microsoft Windows Server 2016. Vendors: Microsoft.

Quick answers

Is CVE-2026-56644 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-56644 being exploited in the wild.
How severe is CVE-2026-56644?
High severity, with a CVSS score of 7.8, published 14 July 2026.
Which products and versions are affected?
Microsoft Windows 10 Version 1607 10.0.14393.0 to 10.0.14393.9339; Microsoft Windows 10 Version 1809 10.0.17763.0 to 10.0.17763.9020; Microsoft Windows 10 Version 21H2 10.0.19044.0 to 10.0.19044.7548; Microsoft Windows 10 Version 22H2 10.0.19045.0 to 10.0.19045.7548; and 2 more.
Is there a fix for CVE-2026-56644?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-56644 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-56644?
Check whether you run Microsoft Windows 10 Version 1607, Microsoft Windows 10 Version 1809, Microsoft Windows 10 Version 21H2 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A use-after-free (UAF) vulnerability exists in the Windows Kernel (CWE-416). The flaw is triggered when the kernel improperly handles objects in memory, allowing an attacker to reuse a memory pointer after it has been freed. To exploit this, an attacker must have local access to the system with low-level user privileges. Successful exploitation enables the attacker to execute code with SYSTEM privileges, leading to a complete compromise of the host's confidentiality, integrity, and availability. Microsoft has released security updates to address this issue across affected versions of Windows 10, Windows 11, and Windows Server.

Affected products

  • Microsoft Windows 10 Version 1607 10.0.14393.0 to 10.0.14393.9339
  • Microsoft Windows 10 Version 1809 10.0.17763.0 to 10.0.17763.9020
  • Microsoft Windows 10 Version 21H2 10.0.19044.0 to 10.0.19044.7548
  • Microsoft Windows 10 Version 22H2 10.0.19045.0 to 10.0.19045.7548
  • Microsoft Windows 11 Version 24H2 10.0.26100.0 to 10.0.26100.8875
  • Microsoft Windows Server 2016 10.0.14393.0 to 10.0.14393.9339

Timeline

  • 2026-07-14: disclosed: Initial publication by Microsoft and NVD
  • 2026-07-14: advisory: Microsoft Security Response Center advisory published

References

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