Stack-based buffer overflow in Microsoft Windows and Windows Server - CVE-2025-54099

Vulnerability identifier: #VU115128

CSH Severity: Low

CVSS v4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-54099

CWE-ID: CWE-121

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to a boundary error in Windows Ancillary Function Driver for WinSock. A local user can trigger stack-based buffer overflow and gain elevated privileges on the target system.

Microsoft Windows
Windows Server

Install updates from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.6332, 10 22H2 10.0.19045.6332, 10 1507 10.0.10240.21128, 10 1607 10.0.14393.8422, 10 1809 10.0.17763.7792, 11 22H2 10.0.22621.5909, 11 23H2 10.0.22631.5909, 11 24H2 10.0.26100.6508, 11 24H2 10.0.26100.6584
Windows Server - addressed in versions 2008 R2 6.1.7601.27929, 2008 6.0.6003.23529, 2012 R2 6.3.9600.22774, 2012 6.2.9200.25675, 2016 10.0.14393.8422, 2019 10.0.17763.7792, 2022 23H2 10.0.25398.1849, 2022 10.0.20348.4106, 2022 10.0.20348.4171, 2025 10.0.26100.6508, 2025 10.0.26100.6584

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-54099

• Privilege escalation in Microsoft Windows Ancillary Function Driver for WinSock