CVE-2025-21333 KEV EXPLOIT
7.8
HIGH · CVSS 3.1 · EPSS 10% (pctl 95)
Patch first
On CISA KEV — known exploited in the wild, due 2025-02-04.
Description
Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability
Scoring
| CVSS | 7.8 (HIGH, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 9.99% — more likely to be exploited than 95% of all CVEs |
| Weakness | CWE-122 |
| On CISA KEV | yes — remediate by 2025-02-04 |
| Public exploit | yes |
| Published | 2025-01-14 |
| Last modified | 2026-06-17 |
CISA KEV
| Name | Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability |
|---|---|
| Added | 2025-01-14 |
| Due | 2025-02-04 |
| Vendor / product | Microsoft / Windows |
| Ransomware use | none reported |
Affected (7)
| Vendor | Product |
|---|---|
| microsoft | windows 10 21h2 |
| microsoft | windows 10 22h2 |
| microsoft | windows 11 22h2 |
| microsoft | windows 11 23h2 |
| microsoft | windows 11 24h2 |
| microsoft | windows server 2022 23h2 |
| microsoft | windows server 2025 |
Public exploits
| Source | Title | Date |
|---|---|---|
| exploit-db | Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege | 2025-09-16 |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333
- https://www.exploit-db.com/exploits/52436
- https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-script
- https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-script
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333
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