CVE-2025-21333

HIGHNVD 7.89.0▲Trending — 5 sources updated this weekExploited in the wild

7.8

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

CVSS v3: 7.8
EG Score: 9.0(high)
EPSS: 99.1%
KEV: ⚠ Exploited

Published

January 14, 2025

Last Modified

November 3, 2025

Advisory Details (5)

Auto-updated Jun 3, 2026

⚠️ Active exploitation confirmed. Patch available. Sources: microsoft, cisa.

cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333

generic

CVE-2025-21333 - Elevated Privilege Exposure in Windows Hyper-V by Microsoft - Mitigation Script - vsociety

https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-script

generic

CVE-2025-21333 - Elevated Privilege Exposure in Windows Hyper-V by Microsoft - Detection Script - vsociety

https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-script

generic🟡 PoC Available

Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege - Windows local Exploit

https://www.exploit-db.com/exploits/52436

microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-122Heap-based Buffer Overflow

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Microsoft MSRCCVE-2025-213332025-01-14
Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

Data Freshness Timeline

(refreshed 20× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-05 12:41 UTCEG score recompute
2026-06-05 12:41 UTCVendor advisory
2026-06-05 12:41 UTCGHSA enrichment
2026-06-05 08:30 UTCEG score recompute
2026-06-05 08:30 UTCVendor advisory
2026-06-05 08:29 UTCGHSA enrichment
2026-06-05 06:10 UTCepss_batch
2026-06-05 06:10 UTCepss_batch
2026-06-05 04:18 UTCEG score recompute
2026-06-05 04:18 UTCVendor advisory
2026-06-05 04:18 UTCGHSA enrichment
2026-06-05 00:06 UTCEG score recompute
2026-06-05 00:06 UTCVendor advisory
2026-06-05 00:06 UTCGHSA enrichment
2026-06-04 19:54 UTCEG score recompute
2026-06-04 19:54 UTCVendor advisory
2026-06-04 19:54 UTCGHSA enrichment
2026-06-04 15:42 UTCEG score recompute
2026-06-04 15:42 UTCVendor advisory
2026-06-04 15:42 UTCGHSA enrichment

Publicly available exploits

(3 references)

Working exploit code is in the public domain (2 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

GitHub PoCnu1lptr0/CVE-2025-21333
First seen May 5, 2026
LPE due to integer truncation in vskrnlintvsp.sys
Open source ↗
Exploit-DBEDB-52436
First seen Sep 16, 2025
Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege
Open source ↗
GitHub PoCMrAle98/CVE-2025-21333-POC
First seen Feb 27, 2025
POC exploit for CVE-2025-21333 heap-based buffer overflow. It leverages WNF state data and I/O ring IOP_MC_BUFFER_ENTRY
Open source ↗

Frequently asked(6)

What is CVE-2025-21333?

CVE-2025-21333 is a high vulnerability published on January 14, 2025. Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

When was CVE-2025-21333 disclosed?

CVE-2025-21333 was first published in the National Vulnerability Database on January 14, 2025, with the most recent update on November 3, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2025-21333 actively exploited?

Yes. CISA added CVE-2025-21333 to the Known Exploited Vulnerabilities catalog on January 14, 2025, affecting Microsoft Windows. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.

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

CVE-2025-21333 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.

Which products are affected by CVE-2025-21333?

CVE-2025-21333 affects Microsoft Windows. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.

How do I remediate CVE-2025-21333?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21333, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-21333

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Is Your Infrastructure Affected by CVE-2025-21333?

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CVE-2025-21333

Published

Last Modified

Advisory Details (5)

Known Exploited Vulnerabilities Catalog | CISA

CVE-2025-21333 - Elevated Privilege Exposure in Windows Hyper-V by Microsoft - Mitigation Script - vsociety

CVE-2025-21333 - Elevated Privilege Exposure in Windows Hyper-V by Microsoft - Detection Script - vsociety

Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege - Windows local Exploit

Security Update Guide - Microsoft Security Response Center

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Publicly available exploits

Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2025-21333?

Same vendor

Same CWE

CVE-2025-21333

📅 Published

🔄 Last Modified

📋 Advisory Details (5)

Known Exploited Vulnerabilities Catalog | CISA

CVE-2025-21333 - Elevated Privilege Exposure in Windows Hyper-V by Microsoft - Mitigation Script - vsociety

CVE-2025-21333 - Elevated Privilege Exposure in Windows Hyper-V by Microsoft - Detection Script - vsociety

Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege - Windows local Exploit

Security Update Guide - Microsoft Security Response Center

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Publicly available exploits

❓ Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2025-21333?

🔗 Related CVEs(same vendor + same CWE)

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Advisory Details (5)

Frequently asked(6)

Related CVEs(same vendor + same CWE)