Junglewise Threat Intelligence

CVE-2026-40408: Microsoft Windows privilege escalation in Kernel-Mode Drivers

CVE-2026-40408 · Severity: high · CVSS 7.8 · Published 2026-05-12

Technologies: Microsoft Windows. Vendors: Microsoft.

Executive brief

A security vulnerability exists in the core drivers that manage the Windows operating system. An attacker who already has basic access to a computer could exploit this flaw to gain full administrative control over the system. This could allow them to bypass security protections, access sensitive data, or install malicious software.

Technical details

A use-after-free (CWE-416) vulnerability exists within Windows Kernel-Mode Drivers. The flaw is triggered when the kernel continues to use a memory pointer after it has been freed, leading to memory corruption. An attacker with local access and low-level privileges can exploit this condition to execute arbitrary code in kernel mode. Successful exploitation results in a complete compromise of the system's integrity, confidentiality, and availability, effectively granting the attacker SYSTEM-level privileges. Microsoft has released security updates to address this issue.

Affected products

  • Microsoft Windows Kernel-Mode Drivers

Timeline

  • 2026-05-12: disclosed
  • 2026-05-12: advisory: Microsoft released the security update guide for this vulnerability.

References

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