CVE-2025-21333 Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow

Exploited in the wild High 7.8 Published Updated

An attacker can exploit a memory corruption flaw in Windows Hyper-V to gain elevated privileges on the host system.

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-2025-21333?

CVE-2025-21333 is a high-severity memory corruption 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-122

Which versions are affected by CVE-2025-21333?

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-2025-21333?

No fix has been published for CVE-2025-21333 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. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-21333 being exploited?

Yes. Attackers have exploited CVE-2025-21333 in the wild since at least 14 Jan 2025.

Public exploit code: 1 Exploit-DB entry and 4 proofs of concept on GitHub.

All Microsoft Windows 10 21h2 vulnerabilities

Sources

Also known as GHSA-gjv6-pfh4-3rff.

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