CVE-2025-54112 is a high-severity use-after-free vulnerability (CWE-416) found in the Microsoft Virtual Hard Drive (VHD) component of Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability allows an authorized local attacker with low privileges to exploit a memory management flaw where the system attempts to use memory after it has been freed, leading to undefined behavior. Exploiting this flaw can enable the attacker to elevate their privileges on the affected system, gaining higher-level access than originally permitted. The vulnerability does not require user interaction but does require local access with some privileges. The CVSS v3.1 base score is 7.0, reflecting high impact on confidentiality, integrity, and availability, but with a higher attack complexity and requiring local privileges. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was reserved in mid-July 2025 and published in early September 2025, indicating recent discovery and disclosure. The use-after-free condition in the VHD driver could allow attackers to execute arbitrary code or cause system crashes, potentially compromising system stability and security.

For European organizations, this vulnerability poses a significant risk especially in environments where Windows 10 Version 1809 is still in use, such as legacy systems or specialized industrial and enterprise setups. Successful exploitation could lead to unauthorized privilege escalation, allowing attackers to bypass security controls, access sensitive data, or deploy further malware with elevated rights. This could compromise confidentiality, integrity, and availability of critical systems. Organizations relying on virtual hard drives for storage or virtualization solutions are particularly at risk. The lack of a patch increases the window of exposure, and although exploitation requires local access, insider threats or attackers who gain initial footholds could leverage this vulnerability to deepen their control. This is especially concerning for sectors with strict data protection requirements under GDPR, as breaches could lead to regulatory penalties and reputational damage.

Given the absence of an official patch, European organizations should implement specific mitigations beyond generic advice: 1) Restrict and monitor local access to systems running Windows 10 Version 1809, limiting user privileges to the minimum necessary to reduce the chance of exploitation. 2) Employ application whitelisting and endpoint detection and response (EDR) tools to detect anomalous behavior indicative of exploitation attempts targeting the VHD component. 3) Disable or limit the use of Virtual Hard Drive features where feasible, especially on systems that do not require them, to reduce the attack surface. 4) Conduct thorough audits of legacy systems to identify and prioritize upgrades or replacements of Windows 10 Version 1809 installations. 5) Implement strict network segmentation to isolate vulnerable systems and prevent lateral movement if exploitation occurs. 6) Prepare incident response plans specifically addressing privilege escalation scenarios and monitor security advisories for forthcoming patches to apply them promptly upon release.