CVE-2025-53804 is a medium-severity vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) that involves the exposure of sensitive information to unauthorized actors. The vulnerability is classified under CWE-200, which pertains to the exposure of sensitive information. Specifically, this flaw exists within the Windows Kernel, a core component responsible for managing system resources and enforcing security boundaries. The vulnerability allows an attacker with authorized local access and low privileges (PR:L) to disclose sensitive information without requiring user interaction (UI:N). The attack vector is local (AV:L), meaning the attacker must have some level of access to the affected system to exploit the vulnerability. The CVSS v3.1 base score is 5.5, reflecting a medium severity level, with a high impact on confidentiality (C:H) but no impact on integrity (I:N) or availability (A:N). The scope remains unchanged (S:U), indicating the vulnerability affects only the vulnerable component and does not propagate to other components. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was reserved in July 2025 and published in September 2025. While the vulnerability does not allow remote exploitation or privilege escalation, the ability to disclose sensitive kernel-level information could aid attackers in further attacks or reconnaissance activities on compromised systems. This vulnerability is particularly relevant for environments where Windows 10 Version 1809 is still in use, especially in legacy or industrial systems that have not been updated to newer versions.

For European organizations, the exposure of sensitive information at the kernel level can have significant consequences. Confidential data leakage could include system internals, security tokens, or other protected information that attackers could leverage to escalate privileges or move laterally within networks. Although exploitation requires local access and does not directly compromise system integrity or availability, the information disclosed could facilitate more severe attacks, such as privilege escalation or targeted intrusions. Organizations in sectors with stringent data protection requirements, such as finance, healthcare, and critical infrastructure, may face compliance risks if sensitive information is leaked. Additionally, legacy systems running Windows 10 Version 1809 are common in some industrial and governmental environments across Europe, increasing the potential attack surface. The lack of a patch at the time of publication means organizations must rely on compensating controls to mitigate risk. Overall, the vulnerability poses a moderate risk but should be addressed promptly to prevent potential escalation chains.

Given the absence of an official patch, European organizations should implement several specific mitigations: 1) Restrict local access to systems running Windows 10 Version 1809 by enforcing strict access controls and limiting administrative privileges to trusted personnel only. 2) Employ endpoint detection and response (EDR) solutions to monitor for unusual local activity that could indicate exploitation attempts. 3) Use application whitelisting and privilege management tools to prevent unauthorized code execution or privilege misuse. 4) Where possible, isolate legacy systems from critical network segments to reduce the risk of lateral movement. 5) Plan and prioritize upgrading affected systems to supported Windows versions with security updates. 6) Conduct regular audits of user accounts and local access permissions to ensure minimal exposure. 7) Educate users about the risks of local exploitation and enforce policies to prevent unauthorized physical or remote local access. These targeted steps go beyond generic advice by focusing on limiting local access and monitoring, which are critical given the local attack vector and lack of remote exploitability.