CVE-2025-21333: Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability
Affects Microsoft WindowsSource GCVE Database
Exploited in the wild · KEV due 4 Feb 2025 · public exploit available (Exploit-DB) : apply the vendor's fix or mitigations to Microsoft Windows now.
Data as of 29 Oct 2026, 23:30 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 14 Jan 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Exploited in the wildExploited: evidence found.
Listed in CISA KEV the same day as disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Microsoft Corporation
, 34 days before disclosure
CVE published
on cve.org
, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, the same day as disclosure
KEV remediation due
US federal deadline
, 21 days after disclosure
First Exploit-DB entry (opens in a new tab)
Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege
, 245 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Description
CVE-2025-21333 is an elevation of privilege vulnerability in the Windows Hyper-V NT Kernel Integration VSP component. It allows an attacker with limited privileges to potentially gain higher privileges on the affected system. The vulnerability has a high severity score of 7.8 and impacts confidentiality, integrity, and availability. No specific affected versions or patches are provided in the available data. Public exploit code exists, but there are no known exploits in the wild at this time.
References
- nvd.nist.gov/vuln/detail/CVE-2025-21333 (opens in a new tab)
- msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333 (opens in a new tab)
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333 (opens in a new tab)
- exploit-db.com/exploits/52436 (opens in a new tab)
- vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-script (opens in a new tab)
- vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-script (opens in a new tab)