Microsoft Windows Hyper-V: Use-after-free allows local privilege escalation

Summary

A use-after-free vulnerability (CWE-416) in Windows Hyper-V allows an authorized local attacker to elevate privileges. Exploitation requires local access and high privileges, and the attack complexity is high, so this is not an internet-facing flaw. Because the CVSS scope is changed, a successful attack can affect resources beyond Hyper-V, with high impact on confidentiality, integrity and availability.

Affected

• Windows 10 Version 1607: 10.0.14393.0 to before 10.0.14393.9688
• Windows 10 Version 1809: 10.0.17763.0 to before 10.0.17763.9487
• Windows 10 Version 21H2: 10.0.19044.0 to before 10.0.19044.7846
• Windows 10 Version 22H2: 10.0.19045.0 to before 10.0.19045.7846
• Windows 11 Version 23H2: 10.0.22631.0 to before 10.0.22631.7711
• Windows 11 Version 24H2: 10.0.26100.0 to before 10.0.26100.9974
• Windows 11 Version 25H2: 10.0.26200.0 to before 10.0.26200.9974
• Windows 11 Version 26H1: 10.0.28000.0 to before 10.0.28000.3501
• Windows 11 Version 26H2: 10.0.26300.0 to before 10.0.26300.9974
• Windows Server 2016 (including Server Core): 10.0.14393.0 to before 10.0.14393.9688
• Windows Server 2019 (including Server Core): 10.0.17763.0 to before 10.0.17763.9487
• Windows Server 2022: 10.0.20348.0 to before 10.0.20348.5870

Fixed in

• Install the November 2026 security update for the affected version (builds listed in the affected section as the first fixed build)
• Windows 10 1607 and Server 2016: 10.0.14393.9688
• Windows 10 1809 and Server 2019: 10.0.17763.9487
• Windows 10 21H2: 10.0.19044.7846
• Windows 10 22H2: 10.0.19045.7846
• Windows 11 23H2: 10.0.22631.7711
• Windows 11 24H2: 10.0.26100.9974
• Windows 11 25H2 and 26H2: 10.0.26200.9974 and 10.0.26300.9974
• Windows 11 26H1: 10.0.28000.3501
• Windows Server 2022: 10.0.20348.5870

Workaround

Unknown. No workaround or mitigation was identified in the sources reviewed. Check the MSRC FAQ for interim mitigations.

Exploitation

• CISA SSVC assessment: exploitation none, not automatable, total technical impact
• No public proof of concept found at the time of review
• No CISA KEV listing found at the time of review; the NVD entry was still awaiting analysis

Our recommendation

• Patch Hyper-V hosts and Hyper-V-enabled endpoints in the next maintenance window, prioritizing Windows Server hosts
• Check for Windows 10 1607 and 1809 systems still in use and upgrade them
• Patch together with the other Hyper-V elevation of privilege fixes from the same November 2026 release
• Restrict local logon and administrative rights on hosts and re-check the CISA KEV catalogue and NVD for changes

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

• MSRC Security Update Guide msrc.microsoft.com
• CVE.org record www.cve.org
• Talos Patch Tuesday November 2026 blog.talosintelligence.com
• CrowdStrike Patch Tuesday analysis November 2026 www.crowdstrike.com
• Action1 Patch Tuesday November 2026 www.action1.com
• Splashtop Patch Tuesday November 2026 www.splashtop.com
• Strix CVE-2026-113861 (third party, unverified versions) www.strix.ai

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 11 Nov 2026, 05:53.