CVE-2025-54912 is a use-after-free vulnerability classified under CWE-416, found in the BitLocker component of Microsoft Windows 10 Version 1809 (build 17763.0). Use-after-free occurs when a program continues to use a pointer after the memory it points to has been freed, leading to undefined behavior including potential code execution or privilege escalation. In this case, an authorized local attacker can exploit the flaw to elevate privileges on the affected system. The vulnerability does not require user interaction, making it easier to exploit once local access is obtained. BitLocker is a full disk encryption feature, and a compromise here could allow attackers to bypass encryption protections or manipulate system security settings. The CVSS v3.1 score is 7.8, indicating high severity with high impact on confidentiality, integrity, and availability. The attack vector is local (AV:L), with low attack complexity (AC:L), requiring privileges (PR:L) but no user interaction (UI:N). The scope remains unchanged (S:U), meaning the impact is confined to the vulnerable component. Although no known exploits are currently reported in the wild, the vulnerability's nature and impact make it a significant risk. The vulnerability was reserved in late July 2025 and published in early September 2025, with no patch links currently available, suggesting that mitigation relies on forthcoming updates and interim controls.

For European organizations, this vulnerability poses a significant risk especially to those still running Windows 10 Version 1809 in their environments. The ability for a local attacker to elevate privileges can lead to full system compromise, allowing attackers to disable security controls, access sensitive data, or disrupt operations. Since BitLocker is widely used for protecting data at rest, exploitation could undermine encryption protections, exposing confidential information. Critical infrastructure, government agencies, and enterprises relying on this Windows version are particularly vulnerable. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, as attackers may develop exploits rapidly after disclosure. The impact on availability, integrity, and confidentiality is high, potentially leading to data breaches, ransomware deployment, or persistent unauthorized access. Organizations with remote or shared access environments are at increased risk due to the local attack vector. The vulnerability also complicates compliance with European data protection regulations such as GDPR if exploited.

1. Prioritize upgrading affected systems from Windows 10 Version 1809 to a supported, patched version of Windows 10 or later, as Microsoft is unlikely to release patches for this older version. 2. Restrict local administrative privileges and limit user accounts with elevated rights to reduce the pool of potential attackers. 3. Implement strict access controls and monitoring on endpoints running Windows 10 1809, especially those using BitLocker. 4. Use endpoint detection and response (EDR) tools to detect suspicious local privilege escalation attempts. 5. Enforce strong physical security controls to prevent unauthorized local access to devices. 6. Regularly audit and review BitLocker configurations and logs for anomalies. 7. Prepare incident response plans specifically addressing local privilege escalation scenarios. 8. Once Microsoft releases patches or mitigations, deploy them promptly. 9. Consider network segmentation to isolate vulnerable systems and reduce lateral movement risk. 10. Educate users and administrators about the risks of local privilege escalation and the importance of maintaining updated systems.