# CVE-2025-21333: Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

CVE-2025-21333 is fixed in 11 products on 1 platform, first by KB5049981, released January 14, 2025. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on January 14, 2025. Patch Radar priority: Patch now.

- Web page: https://patchblox.com/security/cve/CVE-2025-21333
- Priority: Patch now
- CVSS: 7.8 (Important)
- EPSS: 0.1007
- CISA KEV: listed Jan 14, 2025, federal due date Feb 4, 2025
- Exploited (vendor report): yes
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Detected
- Published: Jan 14, 2025
- Weakness: Heap-based Buffer Overflow
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows 10 Version 21H2 for x64-based Systems |  | [KB5049981](https://patchblox.com/security/data/fix/microsoft/kb5049981.md) | Jan 14, 2025 |
| Microsoft | Windows 10 Version 22H2 for x64-based Systems |  | [KB5049981](https://patchblox.com/security/data/fix/microsoft/kb5049981.md) | Jan 14, 2025 |
| Microsoft | Windows 11 Version 22H2 for ARM64-based Systems |  | [KB5050021](https://patchblox.com/security/data/fix/microsoft/kb5050021.md) | Jan 14, 2025 |
| Microsoft | Windows 11 Version 22H2 for x64-based Systems |  | [KB5050021](https://patchblox.com/security/data/fix/microsoft/kb5050021.md) | Jan 14, 2025 |
| Microsoft | Windows 11 Version 23H2 for ARM64-based Systems |  | [KB5050021](https://patchblox.com/security/data/fix/microsoft/kb5050021.md) | Jan 14, 2025 |
| Microsoft | Windows 11 Version 23H2 for x64-based Systems |  | [KB5050021](https://patchblox.com/security/data/fix/microsoft/kb5050021.md) | Jan 14, 2025 |
| Microsoft | Windows 11 Version 24H2 for ARM64-based Systems | 26100.2894 | [KB5050009](https://patchblox.com/security/data/fix/microsoft/kb5050009.md) | Jan 14, 2025 |
| Microsoft | Windows 11 Version 24H2 for x64-based Systems | 26100.2894 | [KB5050009](https://patchblox.com/security/data/fix/microsoft/kb5050009.md) | Jan 14, 2025 |
| Microsoft | Windows Server 2022, 23H2 Edition (Server Core installation) | 25398.1369 | [KB5049984](https://patchblox.com/security/data/fix/microsoft/kb5049984.md) | Jan 14, 2025 |
| Microsoft | Windows Server 2025 | 26100.2894 | [KB5050009](https://patchblox.com/security/data/fix/microsoft/kb5050009.md) | Jan 14, 2025 |
| Microsoft | Windows Server 2025 (Server Core installation) | 26100.2894 | [KB5050009](https://patchblox.com/security/data/fix/microsoft/kb5050009.md) | Jan 14, 2025 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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