CVE-2025-53789 is a high-severity vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw is categorized under CWE-306, which refers to 'Missing Authentication for Critical Function.' Specifically, the vulnerability exists within the Windows StateRepository API, a component responsible for managing state information for applications and system components. Due to the missing authentication controls on critical functions within this API, an attacker who already has some level of local access (authorized local user) can exploit this vulnerability to elevate their privileges on the affected system. This means that a user with limited rights could potentially gain higher privileges, such as administrative or SYSTEM-level access, enabling them to execute arbitrary code, modify system configurations, or disable security controls. The CVSS v3.1 base score is 7.8, indicating a high severity level. The vector string (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) shows that the attack requires local access (AV:L), low attack complexity (AC:L), and low privileges (PR:L) but no user interaction (UI:N). The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), meaning the vulnerability can lead to full compromise of the system. No known exploits are reported in the wild yet, and no patches are linked at the time of publication, suggesting that mitigation may require manual workarounds or awaiting official updates. The vulnerability was reserved on July 9, 2025, and published on August 12, 2025, indicating recent discovery and disclosure. Given the affected product is Windows 10 Version 1809, which is an older release, systems still running this version are at risk if unpatched. The lack of authentication on critical API functions is a serious design flaw that undermines the security boundary between user privileges and system-level operations.

For European organizations, this vulnerability poses a significant risk, especially for those with legacy systems still running Windows 10 Version 1809. The ability for a local attacker to escalate privileges can lead to full system compromise, data breaches, and disruption of critical services. This is particularly concerning for sectors with sensitive data such as finance, healthcare, government, and critical infrastructure. Attackers could leverage this vulnerability to bypass endpoint security controls, deploy ransomware, or move laterally within networks. Since the attack requires local access, the threat is heightened in environments where endpoint security is weak or where insider threats exist. The absence of user interaction means the attack can be automated or executed stealthily once local access is obtained. The high impact on confidentiality, integrity, and availability means that successful exploitation could result in loss of sensitive personal data protected under GDPR, operational downtime, and reputational damage. Additionally, the lack of a patch at the time of disclosure increases the window of exposure for European organizations.

Given the absence of an official patch at the time of disclosure, European organizations should implement the following specific mitigations: 1) Restrict and monitor local access to systems running Windows 10 Version 1809, ensuring only trusted users have physical or remote local access. 2) Employ application whitelisting and endpoint detection and response (EDR) solutions to detect unusual privilege escalation attempts targeting the StateRepository API. 3) Harden user account privileges by enforcing the principle of least privilege and disabling unnecessary local administrator accounts. 4) Use Group Policy or local security policies to restrict access to the StateRepository API or related services if possible, or disable non-essential services that interact with it. 5) Monitor system logs and audit events for suspicious activity related to privilege escalation or API misuse. 6) Plan and prioritize upgrading affected systems to a supported and patched Windows version, as Windows 10 Version 1809 is out of mainstream support and may not receive timely security updates. 7) Educate users and administrators about the risks of local privilege escalation and enforce strict physical security controls to prevent unauthorized local access. These targeted mitigations go beyond generic advice by focusing on access control, monitoring, and system upgrades specific to the affected API and OS version.