CVE-2025-54916 is a stack-based buffer overflow vulnerability identified in the NTFS file system driver of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw arises from improper handling of data within the NTFS driver, allowing an attacker with authorized local access and limited privileges to overflow a stack buffer. This overflow can lead to arbitrary code execution with the privileges of the affected process, potentially escalating to SYSTEM-level privileges. The vulnerability does not require user interaction and has a CVSS v3.1 base score of 7.8, reflecting high severity due to its impact on confidentiality, integrity, and availability. Exploitation requires local access and privileges, which limits remote exploitation but makes it a critical threat in scenarios where attackers have gained initial access. No public exploits or patches are currently available, increasing the urgency for organizations to monitor and prepare mitigations. The vulnerability is categorized under CWE-121, indicating a classic stack-based buffer overflow issue, which is a common and dangerous class of memory corruption vulnerabilities. Given the affected product is Windows 10 Version 1809, which is an older but still widely used version in some enterprise environments, the risk remains significant for unpatched systems.

For European organizations, this vulnerability poses a substantial risk, particularly in sectors where Windows 10 Version 1809 remains in use, such as government agencies, healthcare, manufacturing, and critical infrastructure. Successful exploitation can lead to full system compromise, enabling attackers to steal sensitive data, disrupt operations, or establish persistent footholds. The requirement for local access means that attackers must first breach perimeter defenses or gain physical access, but once inside, they can leverage this vulnerability to escalate privileges and move laterally. This elevates the threat level in environments with shared workstations, remote desktop access, or insufficient endpoint security controls. The impact on confidentiality, integrity, and availability is high, potentially affecting data protection compliance obligations under GDPR and other regulations. Additionally, the lack of known exploits in the wild currently provides a window for proactive defense, but also means organizations must act swiftly to prevent future exploitation.

1. Apply any available security updates or patches from Microsoft immediately once released for Windows 10 Version 1809. 2. Restrict local access to systems running the affected OS version by enforcing strict access controls and limiting administrative privileges. 3. Employ endpoint detection and response (EDR) solutions to monitor for anomalous local activity indicative of exploitation attempts. 4. Disable or restrict NTFS file system features if feasible in the operational environment to reduce attack surface. 5. Enforce strong user authentication and session management policies to prevent unauthorized local access. 6. Conduct regular audits of systems to identify and upgrade outdated Windows 10 versions, prioritizing migration to supported versions with active security updates. 7. Implement network segmentation to limit lateral movement opportunities if local compromise occurs. 8. Educate IT staff and users about the risks of local privilege escalation vulnerabilities and the importance of maintaining updated systems. 9. Prepare incident response plans specifically addressing local privilege escalation scenarios to enable rapid containment and remediation.