SARA / Free Tools / CVE / CVE-2025-21334

CVE-2025-21334 — Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

CVSS

7.8 HIGH

EPSS

6.64% (top 8.90%)

CWE

CWE-416

Published

2025-01-14T18:04:51.608Z

Last modified

2026-02-26T19:09:10.178Z

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

CISA KEV — Actively Exploited

Added to KEV

2025-01-14

BOD 22-01 due

2025-02-04

Ransomware use

Unknown

View KEV detail

01What is this vulnerability?

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

Vendor	Product	Versions
Microsoft	Windows 10 Version 21H2	10.0.19044.0
Microsoft	Windows 10 Version 22H2	10.0.19045.0
Microsoft	Windows 11 version 22H2	10.0.22621.0
Microsoft	Windows 11 version 22H3	10.0.22631.0
Microsoft	Windows 11 Version 23H2	10.0.22631.0
Microsoft	Windows 11 Version 24H2	10.0.26100.0
Microsoft	Windows Server 2022, 23H2 Edition (Server Core installation)	10.0.25398.0
Microsoft	Windows Server 2025	10.0.26100.0
Microsoft	Windows Server 2025 (Server Core installation)	10.0.26100.0

Yes — actively exploited. Added to the CISA KEV catalog on 2025-01-14. Ransomware use: Unknown.

Patch to a fixed version listed in the vendor advisory (see references below).
Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
Hunt historical logs for exploitation indicators — see Detection signatures below.

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

msrc.microsoft.com — https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21334

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