Windows Hyper-V: Use-after-free allows local privilege escalation
Summary
A use-after-free flaw in Windows Hyper-V allows an authorized local attacker to elevate privileges. Exploitation requires a local foothold, such as a compromised user account or malware on the system, and high attack complexity. Hyper-V hosts are most at risk, because a host compromise affects all virtual machines on it.
Affected
- Windows 10 Version 1809, 21H2 and 22H2
- Windows 11 Version 23H2, 24H2, 25H2, 26H1 and 26H2
- Windows Server 2019 (including Server Core), 2022 and 2025 (including Server Core)
- Windows 10 1607 and Windows Server 2016: Unknown.
Fixed in
- Windows 10 1809 and Windows Server 2019: build 10.0.17763.9487 (KB5131085)
- Windows 10 21H2: build 10.0.19044.7846 (KB5131096)
- Windows 10 22H2: build 10.0.19045.7846 (KB5131096)
- Windows 11 23H2: build 10.0.22631.7711 (KB5131087)
- Windows 11 24H2, 25H2 and 26H2: builds 10.0.26100.9974, 10.0.26200.9974 and 10.0.26300.9974 (KB5132061)
- Windows 11 26H1: build 10.0.28000.3501 (KB5132059)
- Windows Server 2022: build 10.0.20348.5870 (KB5131090)
- Windows Server 2025: build 10.0.26100.33822 (KB5131080)
- Fix versions from secondary sources; verify on MSRC before rollout.
Workaround
Unknown. No vendor-documented workaround is known. Interim measure: restrict local interactive logon on Hyper-V hosts and on workstations with Hyper-V enabled.
Exploitation
- Not known to be exploited in the wild.
- Microsoft marks exploit code maturity as Unproven (E:U).
- No public proof of concept found.
Our recommendation
- Install the November 2026 cumulative update on all Windows systems with Hyper-V, starting with Hyper-V hosts.
- Check whether Hyper-V is enabled on each machine, including admin and developer workstations.
- Limit local accounts and interactive logon on Hyper-V hosts.
- Monitor for unusual local privilege changes on these systems.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Critical
- Impact
- Elevation of privilege – Windows Hyper-V
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131085, KB5131096, KB5131090, KB5131087, KB5132061, KB5132043
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Response Center: CVE-2026-113860 msrc.microsoft.com
- CVE Record CVE-2026-113860 www.cve.org
- KB5132059: Windows 11 26H1 security update support.microsoft.com
- IT-Connect: Patch Tuesday November 2026 www.it-connect.tech
- BleepingComputer: KB5132061 and KB5131087 cumulative updates www.bleepingcomputer.com
- Qualys: Patch Tuesday November 2026 review blog.qualys.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 11 Nov 2026, 08:58.
Original description (NVD)
Use after free in Windows Hyper-V allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.