Known exploited vulnerability
CVE-2025-21333
The short answer
CVE-2025-21333 affects Microsoft Windows 10 Version 21H2 and is rated high (CVSS 7.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2025-01-14: attackers are using it, so patch it first. The vendor has linked a patch.
What it is
Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability
Weakness: CWE-122.
Severity
7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploited (CISA KEV)
Yes, since Jan 14, 2025
Federal due date Feb 4, 2025
EPSS, next 30 days
10%
Higher than 96% of scored CVEs
How it can be exploited
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected products
Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 22H2, Windows 11 version 22H3, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows Server 2022, 23H2 Edition (Server Core installation), Windows Server 2025, Windows Server 2025 (Server Core installation). NVD's record lists the exact affected versions.
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333 PatchVendor Advisory
- www.exploit-db.com/exploits/52436 ExploitThird Party AdvisoryVDB Entry
- www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-script MitigationThird Party Advisory
- www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-script MitigationThird Party Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333 US Government Resource
Questions
Is CVE-2025-21333 being exploited?
Yes. CISA added CVE-2025-21333 to its Known Exploited Vulnerabilities catalog on 2025-01-14, with a federal remediation due date of 2025-02-04.
How do I fix CVE-2025-21333?
CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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