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 from improper handling of memory buffers within the mini filter driver, which is responsible for managing cloud file synchronization and caching operations. An authorized attacker with local access can exploit this flaw to overwrite heap memory, leading to arbitrary code execution in kernel mode. Successful exploitation results in elevation of privileges from a low-privileged user to SYSTEM-level privileges, granting the attacker full control over the affected system. The vulnerability does not require user interaction, and the attack complexity is low, but it does require local privileges, meaning the attacker must already have some form of access to the machine. The CVSS v3.1 score of 7.8 reflects the high impact on confidentiality, integrity, and availability, as the attacker can execute arbitrary code and manipulate system processes. No public exploits or proof-of-concept code have been reported yet, but the vulnerability is critical due to the potential for complete system compromise. The flaw was reserved in mid-October 2025 and published in early December 2025, indicating recent discovery and disclosure. The absence of patch links suggests that Microsoft may be preparing or has just released mitigations. The Cloud Files Mini Filter Driver is a core component in Windows 11 for managing cloud storage integration, making this vulnerability particularly impactful in environments relying on cloud file synchronization. Attackers exploiting this vulnerability could bypass security controls, install persistent malware, or disrupt system operations.

For European organizations, the impact of CVE-2025-62454 is significant due to the widespread adoption of Windows 11 in enterprise and government sectors. Successful exploitation allows attackers to gain SYSTEM-level privileges, enabling them to bypass security controls, access sensitive data, and disrupt critical services. This can lead to data breaches, ransomware deployment, and operational downtime. Organizations with cloud-integrated file systems are especially vulnerable, as the flaw resides in the Cloud Files Mini Filter Driver. The vulnerability could facilitate lateral movement within networks, escalating localized breaches into full domain compromises. Critical infrastructure sectors such as finance, healthcare, and public administration in Europe could face severe disruptions. Additionally, the requirement for local access means that insider threats or attackers who have already compromised user credentials pose a heightened risk. The lack of known exploits in the wild currently provides a window for proactive defense, but the high severity score underscores the urgency for mitigation. Failure to address this vulnerability promptly could result in significant financial losses, reputational damage, and regulatory penalties under GDPR and other data protection laws.

1. Apply official Microsoft patches immediately once they become available for Windows 11 Version 25H2 (build 10.0.26200.0). Monitor Microsoft security advisories closely for updates. 2. Restrict local access to systems running the affected Windows version by enforcing strict access controls and using multi-factor authentication for all local logins. 3. Implement application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous behavior related to privilege escalation attempts. 4. Disable or limit the use of cloud file synchronization features if not essential, or isolate affected systems in segmented network zones to reduce attack surface. 5. Conduct regular audits of user privileges and remove unnecessary local administrator rights to minimize the pool of potential attackers. 6. Monitor system logs and security event data for unusual activity involving the Cloud Files Mini Filter Driver or unexpected privilege escalations. 7. Educate IT staff and users about the risks of local privilege escalation vulnerabilities and the importance of reporting suspicious behavior. 8. Maintain up-to-date backups and incident response plans to quickly recover from potential exploitation.