CVE-2025-62454 is a heap-based buffer overflow vulnerability identified in the Windows Cloud Files Mini Filter Driver component of Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). This vulnerability arises due to improper handling of memory buffers in the mini filter driver, which is responsible for managing cloud file synchronization and caching. An authorized local attacker can exploit this flaw by triggering the buffer overflow condition, leading to arbitrary code execution in kernel mode. This enables privilege escalation from a low-privileged user context to SYSTEM-level privileges, compromising the entire system's confidentiality, integrity, and availability. The vulnerability does not require user interaction but does require local access with some privileges (PR:L). The attack complexity is low (AC:L), meaning exploitation is feasible without specialized conditions. Although no public exploits have been reported yet, the vulnerability's nature and impact make it a critical concern for organizations running the affected Windows version. The Cloud Files Mini Filter Driver is integral to Windows' file synchronization features, and exploitation could allow attackers to bypass security controls, install persistent malware, or disrupt system operations. The CVSS v3.1 score of 7.8 reflects high severity, with high impact on confidentiality, integrity, and availability, and a scope limited to the vulnerable system. The vulnerability was reserved in October 2025 and published in December 2025, indicating recent discovery and disclosure.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and government agencies relying on Windows 11 Version 25H2. Successful exploitation can lead to full system compromise, allowing attackers to access sensitive data, disrupt operations, or deploy ransomware and other malware. Organizations with cloud-integrated file systems or those using Windows Cloud Files extensively are particularly vulnerable. The local privilege escalation aspect means that attackers who gain initial access through phishing, insider threats, or other means can escalate privileges to gain full control. This can impact confidentiality by exposing sensitive information, integrity by allowing unauthorized modifications, and availability by enabling denial-of-service or persistent malware. The absence of known exploits in the wild currently provides a window for proactive mitigation, but the high severity demands urgent attention. The impact is amplified in sectors such as finance, healthcare, critical infrastructure, and public administration, where Windows 11 adoption is growing and security requirements are stringent.

1. Apply official Microsoft patches immediately once released for Windows 11 Version 25H2 to remediate the vulnerability. 2. Until patches are available, restrict local access to systems running the affected Windows version by enforcing strict access controls and monitoring local user activities. 3. Implement least privilege principles to minimize the number of users with local access rights that could exploit this vulnerability. 4. Monitor event logs and system behavior for anomalies related to the Cloud Files Mini Filter Driver or unexpected privilege escalations. 5. Use endpoint detection and response (EDR) solutions capable of detecting exploitation attempts targeting kernel-mode components. 6. Educate users and administrators about the risks of local privilege escalation vulnerabilities and the importance of timely patching. 7. Consider disabling or limiting the use of Windows Cloud Files features if not essential, to reduce the attack surface. 8. Maintain up-to-date backups and incident response plans to recover quickly in case of compromise.