Windows: Use after free in Virtual Hard Disk (VHD) Miniport Driver

Summary

A use-after-free flaw (CWE-416) in the Virtual Hard Disk (VHD) Miniport Driver of Windows allows an authorized local attacker to elevate privileges. The attacker needs valid low-privilege access to the system, and the attack complexity is rated high. A successful attack could give the attacker higher rights, up to SYSTEM, on the affected machine.

Affected

• Windows 10 Version 1607 (10.0.14393.0 to below 10.0.14393.9612)
• Windows 10 Version 1809 (10.0.17763.0 to below 10.0.17763.9376)
• Windows 10 Version 21H2 (10.0.19044.0 to below 10.0.19044.7807)
• Windows 10 Version 22H2 (10.0.19045.0 to below 10.0.19045.7807)
• Windows 11 Version 23H2 (10.0.22631.0 to below 10.0.22631.7652)
• Windows 11 Version 24H2 (10.0.26100.0 to below 10.0.26100.9711)
• Windows 11 Version 25H2 (10.0.26200.0 to below 10.0.26200.9711)
• Windows 11 Version 26H1 (10.0.28000.0 to below 10.0.28000.3231)
• Windows 11 Version 26H2 (10.0.26300.0 to below 10.0.26300.9711)
• Windows Server 2012 and Server Core installation (6.2.9200.0 to below 6.2.9200.26434)
• Windows Server 2012 R2 and Server Core installation (6.3.9600.0 to below 6.3.9600.23470)
• Windows Server 2016 (10.0.14393.0 to below 10.0.14393.9612)

Fixed in

• Windows 10 Version 1607: 10.0.14393.9612
• Windows 10 Version 1809: 10.0.17763.9376
• Windows 10 Version 21H2: 10.0.19044.7807
• Windows 10 Version 22H2: 10.0.19045.7807
• Windows 11 Version 23H2: 10.0.22631.7652
• Windows 11 Version 24H2: 10.0.26100.9711
• Windows 11 Version 25H2: 10.0.26200.9711
• Windows 11 Version 26H1: 10.0.28000.3231
• Windows 11 Version 26H2: 10.0.26300.9711
• Windows Server 2012, 2012 R2 and 2016: see the Microsoft Security Update Guide for the build numbers and KB articles

Workaround

• If the VHD Miniport Driver is not required, disable or uninstall it. Test this first, as Microsoft has not documented a procedure in the sources reviewed.
• Restrict local logon and VHD mount rights to trusted users.

Exploitation

• CISA SSVC: exploitation none, automatable no, technical impact total.
• Not listed in the CISA KEV catalog.
• No public proof of concept found.
• EPSS score is low (0.00286).
• No exploitation in the wild known as of 4 November 2026. This reflects the absence of reports, not proof of absence.

Our recommendation

• Install the October 2026 security update on all affected systems and restart them.
• Check whether any Windows 10 Version 1607 devices are still in use. This version is end-of-life; verify its support status on Microsoft's lifecycle pages, as it may receive no fixes.
• Inventory devices that cannot be patched and restrict local logon and VHD mount rights on them.
• Prioritize shared, multi-user, terminal and server systems.
• Priority: medium, raised to high for shared and server systems.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide: CVE-2026-70252 msrc.microsoft.com
• NVD data via Vulners vulners.com
• CVE List record via Vulners vulners.com
• OpenCVE: CVE-2026-70252 app.opencve.io
• VulnCheck/VulnRichment record via Vulners vulners.com

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 4 Nov 2026, 08:55.