Double free in Microsoft Windows and Windows Server - CVE-2025-49667

Vulnerability identifier: #VU112517

CSH Severity: Low

CVSS v4: 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]

CVE-ID: CVE-2025-49667

CWE-ID: CWE-415

Exploitation vector: Local access

Exploit availability: Public exploit is available

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

The vulnerability exists due to a boundary error in Windows Win32 Kernel Subsystem. A local user can pass specially crafted data to the application, trigger double free error and escalate privileges on the target system.

Microsoft Windows
Windows Server

Install updates from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.6093, 10 22H2 10.0.19045.6093, 10 1507 10.0.10240.21073, 10 1607 10.0.14393.8246, 10 1809 10.0.17763.7558, 11 22H2 10.0.22621.5624, 11 23H2 10.0.22631.5624, 11 24H2 10.0.26100.4652
Windows Server - addressed in versions 2008 R2 6.1.7601.27820, 2012 R2 6.3.9600.22676, 2012 6.2.9200.25573, 2016 10.0.14393.8246, 2019 10.0.17763.7558, 2022 23H2 10.0.22621.5472, 2022 23H2 10.0.25398.1732, 2022 10.0.20348.3932, 2025 10.0.26100.4652

• Exploit #11878 - CVE-2025-49667 (August 22, 2025)

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49667

• Privilege escalation in Microsoft Windows Win32 Kernel Subsystem