CVE-2026-25165 is a vulnerability classified under CWE-476 (NULL Pointer Dereference) affecting Microsoft Windows 10 Version 1607 (build 10.0.14393.0). The issue resides in the Windows Performance Counters subsystem, where improper handling of null pointers can cause a dereference leading to a system state that an authorized local attacker can exploit to elevate privileges. This elevation of privilege occurs without requiring user interaction, making it a potent local attack vector. The vulnerability was published on March 10, 2026, with a CVSS v3.1 base score of 7.8, reflecting high severity due to its impact on confidentiality, integrity, and availability. The attack vector is local (AV:L), with low attack complexity (AC:L), requiring privileges (PR:L) but no user interaction (UI:N). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). No known exploits are currently in the wild, and no patches have been linked yet, indicating that mitigation relies on access control and monitoring until official fixes are released. The vulnerability could be exploited by malicious insiders or attackers who have gained limited local access, enabling them to escalate privileges and potentially take full control of the affected system.

The impact of CVE-2026-25165 is significant for organizations running Windows 10 Version 1607, especially those with multiple local user accounts or environments where local access is possible. Successful exploitation allows an attacker with authorized local access to escalate privileges, potentially gaining SYSTEM-level control. This can lead to unauthorized access to sensitive data, modification or deletion of critical system files, installation of persistent malware, and disruption of system availability. In enterprise environments, this could facilitate lateral movement, data breaches, and compromise of critical infrastructure. Since the vulnerability affects confidentiality, integrity, and availability at a high level, the overall risk to organizational security posture is substantial. The lack of public exploits currently reduces immediate risk, but the presence of a known vulnerability with a high CVSS score necessitates proactive mitigation. Legacy systems that have not been updated or migrated to newer Windows versions are particularly vulnerable, increasing the attack surface for threat actors targeting older infrastructure.

To mitigate CVE-2026-25165 effectively, organizations should: 1) Restrict local user access to only trusted personnel and enforce the principle of least privilege to minimize the number of accounts that could exploit this vulnerability. 2) Implement strict access controls and monitoring on systems running Windows 10 Version 1607 to detect unusual privilege escalation attempts. 3) Apply any official patches or updates from Microsoft immediately once they become available, as no patches are currently linked. 4) Consider upgrading affected systems to a more recent, supported Windows version where this vulnerability is not present. 5) Use application whitelisting and endpoint detection and response (EDR) tools to detect and block suspicious activities related to privilege escalation. 6) Conduct regular security audits and vulnerability assessments focusing on legacy systems to identify and remediate similar risks. 7) Educate system administrators and users about the risks of local privilege escalation vulnerabilities and the importance of maintaining updated systems.