How severe is CVE-2025-21335?

CVE-2025-21335 has a CVSS 3.1 base score of 7.8 (HIGH). EPSS estimates a 1.4% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2025-21335: Windows Hyper-V NT Kernel Integration VSP Elevation

CISA Known Exploited Vulnerabilities

Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2025-01-14

Remediation due

2025-02-04

Required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

CISA notes
https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21335 ; https://nvd.nist.gov/vuln/detail/CVE-2025-21335

Description

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

Severity

CVSS 3.1 · CNA7.8 HIGH

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

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Affected Products

Vendor	Product	Affected versions
Microsoft	Windows 10 Version 21H2	10.0.19044.0 to <10.0.19044.5371
Microsoft	Windows 10 Version 22H2	10.0.19045.0 to <10.0.19045.5371
Microsoft	Windows 11 version 22H2	10.0.22621.0 to <10.0.22621.4751
Microsoft	Windows 11 version 22H3	10.0.22631.0 to <10.0.22631.4751
Microsoft	Windows 11 Version 23H2	10.0.22631.0 to <10.0.22631.4751
Microsoft	Windows 11 Version 24H2	10.0.26100.0 to <10.0.26100.2894
Microsoft	Windows Server 2022, 23H2 Edition (Server Core installation)	10.0.25398.0 to <10.0.25398.1369
Microsoft	Windows Server 2025	10.0.26100.0 to <10.0.26100.2894
Microsoft	Windows Server 2025 (Server Core installation)	10.0.26100.0 to <10.0.26100.2894

References

1 Links

Vendor advisories

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

Record Details

Published

2025-01-14

Last updated

2026-06-09

Assigner (CNA)

microsoft

Credited to

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Related Tool Categories

Tool categories that test for or protect against this vulnerability class.

CWE-416 · Use After Free

Fuzzing Binary Exploitation

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.