Microsoft Windows Hyper-V: Denial of service through use-after-free
Summary
Windows Hyper-V on supported Windows 10, Windows 11 and Windows Server builds contains a use-after-free flaw (CWE-416). A network-reachable attacker without privileges or user interaction can crash the hypervisor component, causing a denial of service. Microsoft rates attack complexity as high and the impact as availability only, but a host crash affects every virtual machine on that host.
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 and 26H2: before 10.0.26200.9974 and 10.0.26300.9974
- Windows 11 Version 26H1: 10.0.28000.0 to before 10.0.28000.3501
- Windows Server 2016 (including Server Core): before 10.0.14393.9688
- Windows Server 2019 (including Server Core): before 10.0.17763.9487
- Windows Server 2022: before 10.0.20348.5870
Fixed in
Security update from Microsoft's November 2026 Patch Tuesday for the affected builds listed above. Verify the exact KB numbers in the MSRC Security Update Guide or the Microsoft Update Catalog.
Workaround
Unknown. No workaround or mitigation was confirmed. Apply the security update.
Exploitation
- No public exploit code or proof of concept known at the time of research.
- Rapid7 rates exploitation as less likely and reports no public disclosure.
- CISA SSVC: exploitation none, not automatable, partial technical impact.
- CVE record temporal vector E:U (unproven exploit maturity).
Our recommendation
- Patch Hyper-V hosts with the November 2026 security update in the normal patch cycle, with priority for hosts in segments with broader network access.
- Check whether hosts run older builds such as 1607, 1809 or 21H2 and confirm their support or Extended Security Updates status.
- Restrict network access to Hyper-V hosts and separate them from guest Wi-Fi, IoT and tenant networks.
- Monitor hosts for unexpected reboots or crashes.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Denial of service – 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)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-95913 msrc.microsoft.com
- CVE Record CVE-2026-95913 www.cve.org
- Rapid7 November 2026 Patch Tuesday www.rapid7.com
- VulDB CVE-2026-95913 vuldb.com
- Strix CVE-2026-95913 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, 15:08.
Original description (NVD)
Use after free in Windows Hyper-V allows an unauthorized attacker to deny service over a network.
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.
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