Junglewise Threat Intelligence

CVE-2026-49167: Microsoft Windows Kernel use after free privilege escalation

CVE-2026-49167 · Severity: medium · CVSS 4.7 · Published 2026-07-14

Technologies: Microsoft Windows 10 Version 21H2, Microsoft Windows 11 Version 24H2, Microsoft Windows Server 2022, Microsoft Windows 10 Version 1809, Microsoft Windows 10 Version 22H2, Microsoft Windows 10, Microsoft Windows Server 2019, Microsoft Windows 11. Vendors: Microsoft.

Executive brief

A security vulnerability has been identified in the Windows Kernel, the core component of the Microsoft Windows operating system. An attacker who already has basic access to a system could exploit this flaw to gain higher-level administrative privileges. This could allow them to bypass security restrictions or cause system instability, potentially impacting business operations and data integrity.

Technical details

A use-after-free vulnerability (CWE-416) exists in the Windows Kernel. The flaw is triggered when the kernel attempts to use memory that has already been freed, which can be exploited by a locally authenticated attacker with low privileges. Successful exploitation requires the attacker to win a race condition (High Attack Complexity) but can result in local privilege escalation or a denial-of-service (system crash). 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 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 2019 10.0.17763.0 to 10.0.17763.9020
  • Microsoft Windows Server 2022 10.0.20348.0 to 10.0.20348.5386

Timeline

  • 2026-07-14: advisory: Initial disclosure by Microsoft and NVD publication.
  • 2026-07-14: patched: Security updates made available via Microsoft Update Guide.

References

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