Use-after-free in Microsoft Windows and Windows Server - CVE-2026-113861

Vulnerability details

The vulnerability allows a local privileged user to escalate privileges from a guest virtual machine and execute code on the host in the security context of the virtual machine worker process.

The vulnerability exists due to use-after-free in Windows Hyper-V when a race condition is triggered from a guest virtual machine. A local privileged user can win the race condition to execute code on the host in the security context of the virtual machine worker process.

Affected software

How to mitigate CVE-2026-113861

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-113861
• https://support.microsoft.com/help/5131291

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Windows