CVE-2025-21334 Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free
A use-after-free flaw in Windows Hyper-V allows attackers to escalate privileges on affected Windows systems.
- Exploited in the wild
- Since 14 Jan 2025
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-21334?
CVE-2025-21334 is a high-severity use after free vulnerability in Microsoft Windows 10 21h2, published on 14 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability
Weakness: CWE-416
Which versions are affected by CVE-2025-21334?
It affects 7 products.
Products include Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows Server 2022 23h2 and 1 more.
How do I fix CVE-2025-21334?
No fix has been published for CVE-2025-21334 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 4 Feb 2025.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-21334 being exploited?
Yes. Attackers have exploited CVE-2025-21334 in the wild since at least 14 Jan 2025.
Other vulnerabilities in Microsoft Windows 10 21h2
- CVE-2025-21333 Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow
- CVE-2025-21335 Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free
- CVE-2026-42904 Windows TCP/IP Elevation of Privilege Vulnerability
- CVE-2026-105733 Windows Hyper-V Remote Code Execution Vulnerability
- CVE-2026-69945 Windows AppX Deployment Extensions Elevation of Privilege Vulnerability
Sources
Also known as GHSA-3hcq-fqcw-cvgf.