Heap-based buffer overflow in Microsoft Windows and Windows Server - CVE-2025-27478

Vulnerability identifier: #VU107258

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-2025-27478

CWE-ID: CWE-122

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Windows Local Security Authority (LSA). A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code on the target system with elevated privileges.

Microsoft Windows
Windows Server

Install update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.5737, 10 22H2 10.0.19045.5737, 10 1607 10.0.14393.7970, 10 1809 10.0.17763.7137, 11 22H2 10.0.22621.5191, 11 23H2 10.0.22631.5191, 11 24H2 10.0.26100.3775
Windows Server - addressed in versions 2008 R2 6.1.7601.27670, 2008 6.0.6003.23220, 2012 R2 6.3.9600.22523, 2012 6.2.9200.25423, 2016 10.0.14393.7970, 2019 10.0.17763.7137, 2022 23H2 10.0.25398.1551, 2022 10.0.20348.3454, 2025 10.0.26100.3775

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-27478

• Multiple vulnerabilities in Microsoft Windows Local Security Authority (LSA)