CVE-2025-59255 is a heap-based buffer overflow vulnerability classified under CWE-122, located in the Windows Desktop Window Manager (DWM) Core Library of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw allows an attacker who already has authorized local access with limited privileges to execute a buffer overflow attack on the heap memory, potentially overwriting critical data structures. This memory corruption can be exploited to escalate privileges, granting the attacker higher-level permissions on the affected system. The vulnerability does not require user interaction (UI:N) and has a low attack complexity (AC:L), meaning exploitation is feasible with limited effort once local access is obtained. The CVSS v3.1 base score of 7.8 reflects its high impact on confidentiality, integrity, and availability (all rated high), with the scope unchanged (S:U). Although no public exploits are currently known, the vulnerability's nature makes it a prime candidate for future exploitation, especially in environments where Windows 10 1809 remains in use. The absence of direct patch links indicates that mitigation may rely on forthcoming security updates or manual workarounds. The vulnerability's local privilege escalation vector is critical because it can be combined with other attack methods to achieve full system compromise.

For European organizations, the impact of CVE-2025-59255 is significant, particularly for those still operating Windows 10 Version 1809 in production environments. Successful exploitation can lead to unauthorized privilege escalation, enabling attackers to bypass security controls, install persistent malware, or access sensitive data. This can compromise the confidentiality of personal and corporate information, violate data protection regulations such as GDPR, and disrupt business operations. The integrity of systems and data can be undermined, and availability may be affected if attackers deploy destructive payloads or ransomware. Critical sectors including finance, healthcare, government, and industrial control systems are at heightened risk due to the potential for lateral movement and escalation within networks. The vulnerability's local attack vector means that insider threats or attackers who have gained initial footholds via phishing or other means can leverage this flaw to deepen their access. The lack of known exploits currently provides a window for proactive defense, but the high severity score underscores the urgency of addressing this issue.

European organizations should take immediate and specific actions to mitigate CVE-2025-59255 beyond generic advice. First, identify and inventory all systems running Windows 10 Version 1809 to assess exposure. Since no direct patch link is provided, monitor Microsoft's official security advisories for the release of a dedicated patch or cumulative update addressing this vulnerability. In the interim, restrict local access to affected systems by enforcing strict access controls and limiting administrative privileges to essential personnel only. Implement application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous behavior indicative of privilege escalation attempts. Conduct regular audits of user accounts and privilege assignments to minimize the risk of exploitation. Encourage migration plans to newer, supported Windows versions that receive ongoing security updates. Additionally, enhance network segmentation to contain potential breaches and reduce lateral movement opportunities. Educate IT staff about this specific vulnerability to improve incident response readiness. Finally, maintain up-to-date backups and test recovery procedures to mitigate potential damage from exploitation.