CVE-2025-59203 is a vulnerability classified under CWE-532, which pertains to the insertion of sensitive information into log files. Specifically, this issue affects the Windows StateRepository API in Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). The vulnerability arises because the API logs sensitive data in an insecure manner, allowing an authorized attacker with local access and low privileges (PR:L) to read these logs and disclose confidential information. The vulnerability does not require user interaction (UI:N) and has a low attack complexity (AC:L), but it is limited to local access (AV:L). The scope is unchanged (S:U), meaning the impact is confined to the vulnerable component. The CVSS v3.1 base score is 5.5, reflecting a medium severity primarily due to the high confidentiality impact (C:H) but no impact on integrity (I:N) or availability (A:N). The vulnerability was published on October 14, 2025, with no known exploits in the wild and no patches currently available. The flaw could lead to unauthorized disclosure of sensitive information such as credentials, tokens, or configuration details stored or processed by the StateRepository API, which could be leveraged for further local privilege escalation or lateral movement if combined with other vulnerabilities. Since the attacker must have local access and some privileges, remote exploitation is not feasible, but insider threats or compromised local accounts pose a risk. The vulnerability highlights the importance of secure logging practices and proper handling of sensitive data within system components.

For European organizations, this vulnerability poses a risk of sensitive data leakage on Windows 11 25H2 systems. Confidential information exposure could lead to further attacks such as privilege escalation or lateral movement within networks, especially in environments where local access controls are weak or where multiple users share systems. Critical sectors such as finance, healthcare, government, and industrial control systems could be particularly impacted if attackers gain access to sensitive operational or credential data. The medium severity indicates that while the vulnerability is not immediately exploitable remotely, the potential confidentiality breach could have significant consequences if combined with other vulnerabilities or insider threats. Organizations with strict data protection regulations like GDPR must consider the risk of unauthorized data exposure and potential compliance violations. The lack of current exploits reduces immediate risk but also means organizations should proactively monitor and prepare for patch deployment.

To mitigate this vulnerability, European organizations should implement strict access controls on local systems to limit who can read log files generated by the StateRepository API. Regularly audit and monitor log files for sensitive information exposure and unusual access patterns. Employ endpoint detection and response (EDR) solutions to detect suspicious local activity. Until a patch is released by Microsoft, consider applying temporary workarounds such as restricting permissions on log directories or disabling the affected API if feasible without disrupting operations. Educate system administrators and users about the risk of local privilege misuse and enforce the principle of least privilege to minimize the number of users with local access rights. Once Microsoft releases a patch, prioritize its deployment across all affected Windows 11 25H2 systems. Additionally, review and enhance logging configurations to avoid logging sensitive data in the future and implement data masking or encryption for sensitive log entries where possible.