#VU103779 Double free in Windows Server - CVE-2025-21182

Vulnerability identifier: #VU103779

Vulnerability risk: Low

CVSSv4.0: 4.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21182

CWE-ID: CWE-415

Exploitation vector: Local

Exploit availability: No

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

Vendor: Microsoft

Description

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

The vulnerability exists due to a boundary error in Windows Resilient File System (ReFS) Deduplication Service. A local attacker can win a race condition, trigger double free error and gain elevated privileges on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Windows Server: before 2016, 2025, 2016, 2016

---

External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21182

---

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?

No. We are not aware of malware exploiting this vulnerability.