CVE-2025-49667 is a high-severity vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0), specifically within the Win32K component related to ICOMP. The vulnerability is classified as a double free condition (CWE-415), which occurs when the system attempts to free the same memory location twice. This flaw can lead to memory corruption, potentially allowing an authorized local attacker to escalate privileges on the affected system. The attack vector requires local access with some level of privileges (PR:L), but no user interaction is needed (UI:N). The vulnerability impacts confidentiality, integrity, and availability, as indicated by the CVSS vector (C:H/I:H/A:H). The flaw arises from improper memory management in the kernel-mode graphics subsystem, which is critical for rendering and user interface operations. Exploiting this vulnerability could allow an attacker to execute arbitrary code at elevated privileges, thereby gaining control over the system or bypassing security restrictions. Although no known exploits are currently observed in the wild, the vulnerability's characteristics and high CVSS score suggest that it is a significant risk if left unpatched. The vulnerability was reserved in June 2025 and published in July 2025, indicating recent discovery and disclosure. No official patches or mitigations have been linked yet, which may leave systems exposed until updates are released.

For European organizations, this vulnerability poses a significant risk, especially for those still operating legacy systems running Windows 10 Version 1809. The ability for an authorized local attacker to escalate privileges can lead to full system compromise, data breaches, and disruption of critical services. 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 vulnerability could be exploited by insiders or through lateral movement after initial access, increasing the risk of widespread compromise within networks. Additionally, the high impact on confidentiality, integrity, and availability means that successful exploitation could result in theft of sensitive information, unauthorized modification of data, and denial of service conditions. Given the lack of known exploits in the wild, the immediate risk may be moderate, but the potential for future exploitation is high, especially if threat actors develop reliable exploit code. The absence of a patch at the time of disclosure further elevates the risk for organizations that have not upgraded or mitigated the vulnerability through other means.

European organizations should prioritize upgrading from Windows 10 Version 1809 to a more recent and supported Windows version that includes security fixes for this vulnerability. If immediate upgrade is not feasible, organizations should implement strict access controls to limit local user privileges, ensuring that only trusted personnel have the necessary rights to operate on affected systems. Employing application whitelisting and endpoint detection and response (EDR) solutions can help detect and prevent exploitation attempts. Network segmentation should be enforced to contain potential lateral movement following privilege escalation. Monitoring system logs and kernel events for unusual activity related to Win32K or memory management anomalies can provide early warning signs of exploitation attempts. Organizations should also stay alert for official patches or security advisories from Microsoft and apply them promptly once available. Finally, conducting regular security awareness training to reduce the risk of insider threats and maintaining up-to-date asset inventories to identify vulnerable systems are critical steps.