#VU102616 Use-after-free in Windows and Windows Server - CVE-2025-21334

Vulnerability identifier: #VU102616

Vulnerability risk: High

CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2025-21334

CWE-ID: CWE-416

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Windows
Operating systems & Components / Operating system
Windows Server
Operating systems & Components / Operating system

Vendor: Microsoft

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error in Windows Hyper-V NT Kernel Integration VSP component. A local user can execute arbitrary code with SYSTEM privileges.

Note, the vulnerability is being actively exploited in the wild.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Windows: before 10 21H2, 10 22H2, 11 22H2, 11 23H2, 11 24H2, 10 21H2, 10 21H2, 10 21H2, 10 21H2, 10 21H2

Windows Server: before 2016, 2022 23H2, 2025, 2016, 2016, 2016

---

External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21334

---

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.