VulnerabilityAnalyzed
CVE-2025-21333
Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability
KEVHIGH 7.8EPSS 9.99%
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 4 February 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 9.99% probability · 95th percentile
- CISA KEV
- Listed 14 January 2025 · due 4 February 2025
- Weakness
- CWE-122
- Affected
- 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
- Source
- secure@microsoft.com
CISA notes
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21333 ; https://nvd.nist.gov/vuln/detail/CVE-2025-21333
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333Patch, Vendor Advisory
- https://www.exploit-db.com/exploits/52436Exploit, Third Party Advisory, VDB Entry
- https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-scriptMitigation, Third Party Advisory
- https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-scriptMitigation, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.