CVE-2025-53804 is an information disclosure vulnerability classified under CWE-200 affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The vulnerability resides in the Windows Kernel, where an authorized local attacker with low privileges can exploit the flaw to disclose sensitive information. This exposure does not affect system integrity or availability but compromises confidentiality, potentially leaking data that could be leveraged for further attacks such as privilege escalation or lateral movement. The attack vector is local (AV:L), requiring the attacker to have some level of authenticated access (PR:L) but no user interaction (UI:N). The scope is unchanged (S:U), meaning the impact is limited to the vulnerable system without affecting other components. The CVSS v3.1 base score is 5.5, indicating medium severity. No patches or exploit code are currently available, and no known active exploitation has been reported. The vulnerability was reserved in July 2025 and published in September 2025. Given the affected version is Windows 10 1809, which is an older release, many organizations may have already migrated to newer versions, but legacy systems remain at risk. The lack of a patch necessitates immediate mitigation through access control and monitoring. The vulnerability's exploitation could facilitate attackers in gathering sensitive kernel-level information, aiding in crafting more sophisticated attacks or bypassing security controls.

For European organizations, the primary impact of CVE-2025-53804 is the unauthorized disclosure of sensitive information from the Windows Kernel on systems running Windows 10 Version 1809. This could lead to leakage of critical data such as system internals, security tokens, or other confidential information that attackers could use to escalate privileges or move laterally within networks. Although the vulnerability does not directly compromise system integrity or availability, the confidentiality breach can be a stepping stone for more damaging attacks. Organizations in sectors with high security requirements, such as government, finance, healthcare, and critical infrastructure, are particularly at risk if legacy Windows 10 1809 systems remain in use. The local attack vector limits the threat to insiders or attackers who have already gained some access, but this does not diminish the risk in environments where endpoint security is weak or where attackers can leverage social engineering to gain initial footholds. The absence of known exploits reduces immediate risk but also means organizations should proactively address the vulnerability before exploit code emerges.

To mitigate CVE-2025-53804, European organizations should: 1) Restrict local access to systems running Windows 10 Version 1809 by enforcing strict user account controls and limiting administrative privileges. 2) Implement robust endpoint detection and response (EDR) solutions to monitor for unusual kernel-level activities or attempts to access sensitive system information. 3) Conduct thorough audits of systems to identify any running the affected Windows 10 1809 build and prioritize their upgrade to supported Windows versions with security patches. 4) Apply network segmentation to isolate legacy systems and reduce the risk of lateral movement if an attacker gains local access. 5) Educate users and administrators about the risks of local privilege abuse and enforce strong authentication mechanisms to prevent unauthorized access. 6) Monitor vendor advisories for the release of patches or security updates addressing this vulnerability and apply them promptly once available. 7) Consider deploying application whitelisting and restricting execution of untrusted code to minimize the attack surface. These steps go beyond generic advice by focusing on access control, monitoring, and proactive system upgrades tailored to the specific vulnerability context.