CVE-2026-25165: 
vulnerability analysis and mitigation

CVE-2026-25165 is a null pointer dereference vulnerability in Windows Performance Counters that allows a locally authenticated, low-privileged attacker to elevate privileges to SYSTEM level. Disclosed on March 10, 2026, as part of Microsoft's March 2026 Patch Tuesday, it affects a wide range of Windows versions including Windows 10 (1607, 1809, 21H2, 22H2), Windows 11 (23H2, 24H2, 25H2, 26H1), Windows Server 2012/2012 R2, 2016, 2019, 2022, 2022 23H2, and 2025. It carries a CVSS v3.1 base score of 7.8 (High) (Microsoft MSRC).

The vulnerability is rooted in a null pointer dereference (CWE-476) within the Windows Performance Counters subsystem. An attacker with low-privilege local access can trigger the dereference — requiring no user interaction — to corrupt memory in a manner that leads to privilege escalation. The attack vector is local, with low attack complexity and no requirement for elevated privileges prior to exploitation, making it straightforward for any authenticated user to attempt (Microsoft MSRC).

Successful exploitation allows a low-privileged local attacker to gain SYSTEM-level privileges on the affected Windows host, resulting in high confidentiality, integrity, and availability impact. This enables complete system compromise, including unauthorized access to sensitive data, arbitrary system modification, and potential installation of persistent malware or backdoors. The broad scope of affected Windows versions — spanning client and server editions from Windows 10 1607 through Windows Server 2025 — significantly widens the potential attack surface (Microsoft MSRC).

Microsoft released patches on March 10, 2026, addressing this vulnerability across all affected platforms. Administrators should apply the following minimum build versions: Windows Server 2025 (10.0.26100.32463), Windows Server 2022 (10.0.20348.4830), Windows Server 2022 23H2 (10.0.25398.2207), Windows Server 2019 (10.0.17763.8511), Windows Server 2016 (10.0.14393.8957), Windows 11 23H2 (10.0.22631.6783), Windows 11 24H2 (10.0.26100.7979), Windows 11 25H2 (10.0.26200.7979), Windows 11 26H1 (10.0.28000.1719), Windows 10 22H2 (10.0.19045.7058), Windows 10 21H2 (10.0.19044.7058), and Windows 10 1607/1809 (10.0.14393.8957 / 10.0.17763.8511). As interim mitigations, organizations should enforce the principle of least privilege for local user accounts, monitor Performance Counter activity for anomalies, and consider restricting access to Windows Performance Counters where operationally feasible (Microsoft MSRC).

The vulnerability was covered as part of broader March 2026 Patch Tuesday roundups by multiple security outlets including BleepingComputer, Rapid7, Zero Day Initiative, Sophos, and CyberSecurityNews, which collectively noted the patch addressed 79 vulnerabilities including two zero-days (unrelated to this CVE). No specific researcher commentary or notable social media discussion focused exclusively on CVE-2026-25165 has been identified, consistent with its lower EPSS score and lack of public exploit code (Zero Day Initiative, Rapid7, Sophos).