CVE-2025-62467 is an integer overflow or wraparound vulnerability identified in the Windows Projected File System (ProjFS) component of Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). The flaw stems from improper handling of integer values within the ProjFS code, which can cause arithmetic operations to exceed the maximum value an integer can hold, resulting in wraparound behavior. This can lead to memory corruption or logic errors that an attacker can leverage to escalate privileges locally. The vulnerability requires the attacker to have some level of local access (limited privileges) but does not require user interaction, making it a potent vector for privilege escalation. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and no user interaction needed. The vulnerability is classified under CWE-190 (Integer Overflow or Wraparound). Although no exploits are currently known in the wild, the absence of patches increases the risk of future exploitation. The flaw could allow attackers to bypass security controls, execute arbitrary code with elevated privileges, and potentially take full control of affected systems. ProjFS is used to project a hierarchical file system structure, often leveraged by development tools and system utilities, meaning the vulnerability could affect a broad range of applications relying on this subsystem.

For European organizations, this vulnerability poses a significant risk as it enables local attackers to escalate privileges and potentially gain full control over Windows 11 systems running the affected build. This could lead to unauthorized access to sensitive data, disruption of critical services, and compromise of system integrity. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly vulnerable due to the sensitive nature of their data and operations. The ability to elevate privileges locally means that attackers who gain initial footholds through other means (e.g., phishing, insider threats) could leverage this vulnerability to deepen their access and evade detection. The lack of a patch at the time of disclosure increases the window of exposure. Additionally, since Windows 11 adoption is growing across Europe, the scope of affected systems is broad, increasing the potential impact on business continuity and data protection compliance obligations under regulations like GDPR.

1. Monitor Microsoft security advisories closely and apply official patches immediately once released to address CVE-2025-62467. 2. Restrict local access to Windows 11 systems, especially for users who do not require elevated privileges, to reduce the risk of exploitation. 3. Implement strict access controls and use least privilege principles to limit the ability of users to execute code or access the ProjFS subsystem unnecessarily. 4. Employ endpoint detection and response (EDR) solutions to monitor for unusual local privilege escalation attempts or anomalous behavior related to file system operations. 5. Conduct regular audits of user accounts and permissions to identify and remediate excessive privileges. 6. Educate users and administrators about the risks of local privilege escalation vulnerabilities and encourage prompt reporting of suspicious activity. 7. Consider network segmentation to isolate critical systems and reduce the impact of a compromised endpoint. 8. Use application whitelisting and code integrity policies to prevent unauthorized code execution that could exploit this vulnerability.