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Vulnerabilities

Vulnerability · CVE-2025-21333

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

Published Jan 14, 2025 · catalog updated Jun 17, 2026 · Microsoft Windows

Patch now

CVE-2025-21333 is in the CISA known-exploited catalog, due Feb 4, 2025. Confirm Microsoft Windows against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
High7.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
9.99%
Remediation
Remediation guidance
Affected products
cpe microsoft/windows 10 21h2 · cpe microsoft/windows 10 22h2 · cpe microsoft/windows 11 22h2 · cpe microsoft/windows 11 23h2 · cpe microsoft/windows 11 24h2 · cpe microsoft/windows server 2022 23h2

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

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe microsoft/windows 10 21h2version unspecified
  • cpe microsoft/windows 10 22h2version unspecified
  • cpe microsoft/windows 11 22h2version unspecified
  • cpe microsoft/windows 11 23h2version unspecified
  • cpe microsoft/windows 11 24h2version unspecified
  • cpe microsoft/windows server 2022 23h2version unspecified
  • cpe microsoft/windows server 2025version unspecified
  • vendor Microsoft Windowsversion unspecified

How to fix CVE-2025-21333

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2025-21333 is in the CISA known-exploited catalog, due Feb 4, 2025. Confirm Microsoft Windows against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What should an analyst verify?

CWE-122: Heap-based Buffer Overflow. EPSS 9.99%. The CISA KEV listing is the exploitation evidence. A public exploit reference is linked in Sources. That is not the same as confirmed exploitation. Use the source links for the original advisory.

Technology hubs

Windows security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jan 14, 2025 · Catalog

    Detected

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

  2. Jan 14, 2025 · CISA KEV

    Known exploited

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

  3. Feb 4, 2025 · CISA KEV

    Remediation due

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

  4. Jun 17, 2026 · Catalog

    Updated

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

Sources

  • CISA KEVConfirmed exploitationCVE-2025-21333

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

    cisa.gov
  • CVE.orgVulnerability recordCVE-2025-21333

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-21333

    30-day exploitation probability 10.0%

    first.org
  • Exploit DatabasePublic exploit reference52436

    Public archive entry. The exploit body is not stored here.

    exploit-db.com
  • NIST NVDVulnerability recordCVE-2025-21333

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

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2025-21333

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

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.