CVE-2025-59203 is a vulnerability identified in Microsoft Windows 11 Version 25H2 (build 10.0.26200.0) involving the Windows StateRepository API. The flaw is categorized under CWE-532, which pertains to the insertion of sensitive information into log files. Specifically, the API improperly logs sensitive data, which can be accessed by an authorized attacker with local access and limited privileges (PR:L). The vulnerability does not require user interaction (UI:N) and affects confidentiality (C:H) but not integrity or availability. The attack vector is local (AV:L), meaning an attacker must have some level of access to the system to exploit it. The vulnerability is unexploited in the wild as of the publication date (October 14, 2025), and no patches have been released yet. The CVSS v3.1 base score is 5.5, reflecting a medium severity due to the combination of local access requirements and high confidentiality impact. The flaw could allow attackers to gain access to sensitive information such as credentials, tokens, or configuration details logged by the StateRepository API, potentially facilitating further attacks or privilege escalation. Since the vulnerability only exposes information locally, remote exploitation is not feasible, but insider threats or compromised local accounts pose a risk. The lack of available patches necessitates interim mitigations to protect sensitive log data and monitor local access.

For European organizations, this vulnerability poses a risk primarily to confidentiality within Windows 11 25H2 environments. Organizations with multi-user systems, shared workstations, or environments where local user accounts have limited but non-administrative privileges are particularly at risk. Disclosure of sensitive information could lead to credential theft, unauthorized access to internal systems, or lateral movement within networks. Critical sectors such as finance, healthcare, and government, which often use Windows 11 and handle sensitive data, may face increased risk if attackers gain local access. However, the impact is somewhat limited by the requirement for local access and the absence of integrity or availability effects. The vulnerability could be exploited by malicious insiders or attackers who have already compromised a low-privilege account, potentially escalating their capabilities. Given the medium severity, the threat should be prioritized in environments with high security requirements and where local access controls are less stringent.

Until an official patch is released, European organizations should implement specific mitigations to reduce risk. These include: 1) Restricting access to log files generated by the Windows StateRepository API through strict file permissions and auditing; 2) Enforcing the principle of least privilege to limit the number of users with local access and ensuring accounts have minimal rights; 3) Monitoring local system logs and user activities for unusual access patterns or attempts to read sensitive logs; 4) Employing endpoint detection and response (EDR) solutions to detect suspicious local behavior; 5) Using application whitelisting and hardening techniques to prevent unauthorized execution of tools that could exploit the vulnerability; 6) Preparing for rapid deployment of patches once Microsoft releases updates by maintaining an effective patch management process; 7) Educating users about the risks of local credential compromise and insider threats; 8) Considering additional encryption or obfuscation of sensitive data in logs if feasible. These targeted measures go beyond generic advice by focusing on local access controls and monitoring specific to the vulnerability's nature.