Is CVE-2025-21333 in the CISA KEV catalog?

Yes. CVE-2025-21333 is on the CISA Known Exploited Vulnerabilities list, added 2025-01-14.

What is the CVSS severity of CVE-2025-21333?

CVE-2025-21333 has a CVSS v3 base score of 7.8 (HIGH).

What is the EPSS score for CVE-2025-21333?

CVE-2025-21333 has an EPSS score of 9.80% (95th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2025-21333?

Install KB5049981 for Windows 10 Version 21H2. Fixes are available for 8 affected products.

CVE & CISA-KEV Catalog

CVE-2025-21333

HIGHCISA KEVEPSS 95th pctl

7.8

CVSS v3

NVD

Description

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

CWE-122Heap-based Buffer Overflow

How to fix

Remediation Available

Windows 10 Version 21H2Windows

Install:KB5049981Microsoft

Windows 10 Version 22H2Windows

Install:KB5049981Microsoft

Windows 11 Version 22H2Windows

Install:KB5050021Microsoft

Windows 11 Version 23H2Windows

Install:KB5050021Microsoft

Windows 11 Version 24H2Windows

Install:KB5050009Microsoft

Windows Server 2022, 23H2 Edition (Server Core installation)Windows

Install:KB5049984Microsoft

Windows Server 2025Windows

Install:KB5050009Microsoft

Windows Server 2025 (Server Core installation)Windows

Install:KB5050009Microsoft

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

9.80%probability of exploitation in 30 days

95thpercentile

Very high risk: more likely to be exploited than 95% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability

Microsoft Windows Hyper-V NT Kernel Integration VSP contains a heap-based buffer overflow vulnerability that allows a local attacker to gain SYSTEM privileges.

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

Remediation due: 2025-02-04

References

Patch1

msrc.microsoft.com

Exploit1

exploit-db.com

Mitigation2

Government Resource1

cisa.gov

Related Vulnerabilities

Other CWE-122 (Heap-based Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2015-3113	Critical	9.8	100%	KEV	Fix
CVE-2024-26256	High	7.8	88%	-	Fix
CVE-2020-25687	Medium	5.9	87%	-	Fix
CVE-2009-3459	High	8.8	87%	KEV	Fix
CVE-2021-21017	High	8.8	86%	KEV	-
CVE-2020-25683	Medium	5.9	86%	-	Fix

Embed a live status badge for CVE-2025-21333

Markdown

[![CVE-2025-21333](https://tridentstack.com/cve/badge/CVE-2025-21333.svg)](https://tridentstack.com/cve/CVE-2025-21333)

HTML

<a href="https://tridentstack.com/cve/CVE-2025-21333"><img src="https://tridentstack.com/cve/badge/CVE-2025-21333.svg" alt="CVE-2025-21333"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

See how it works Start freeThis CVE lookup is free and always will be.

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-03.