CVE-2025-54911 is a use-after-free vulnerability (CWE-416) identified in the BitLocker component of Microsoft Windows 10 Version 1809 (build 17763.0). Use-after-free vulnerabilities occur when a program continues to use memory after it has been freed, leading to undefined behavior such as memory corruption, crashes, or arbitrary code execution. In this case, an authorized attacker with local access and limited privileges can exploit this flaw to elevate their privileges on the system. The vulnerability requires some user interaction, indicating that the attacker might need to trigger a specific action or run a crafted application. The CVSS v3.1 base score is 7.3, reflecting high severity with high impact on confidentiality, integrity, and availability (all rated high). The attack vector is local, with low attack complexity and low privileges required, but user interaction is necessary. The scope remains unchanged, meaning the exploit affects only the vulnerable component without impacting other system components. No public exploits or active exploitation in the wild have been reported yet. The vulnerability was reserved on July 31, 2025, and published on September 9, 2025. No patch links are currently provided, suggesting that organizations should monitor for updates or consider upgrading to a newer Windows version. BitLocker is a disk encryption feature widely used to protect data confidentiality, so exploitation could undermine data security and system integrity.

For European organizations, this vulnerability poses a significant risk, especially those relying on Windows 10 Version 1809 with BitLocker enabled to protect sensitive data. Successful exploitation could allow attackers to escalate privileges locally, potentially leading to full system compromise, data theft, or disruption of services. Critical sectors such as finance, healthcare, government, and infrastructure that use BitLocker for data protection are particularly vulnerable. The impact extends to confidentiality, as encrypted data could be exposed; integrity, as attackers could modify system files or configurations; and availability, through potential system crashes or denial of service. Since the vulnerability requires local access, insider threats or attackers who have gained initial footholds could leverage this flaw to deepen their control. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as exploit code may emerge. European organizations with legacy systems or delayed patching practices face higher exposure. Additionally, compliance with data protection regulations like GDPR could be jeopardized if data confidentiality is compromised.

Given the absence of an official patch at this time, European organizations should prioritize the following mitigations: 1) Upgrade affected systems from Windows 10 Version 1809 to a supported, patched Windows version where this vulnerability is addressed. 2) Restrict local user access to systems running vulnerable versions, enforcing strict access controls and least privilege principles. 3) Monitor and audit local user activities for suspicious behavior indicative of privilege escalation attempts. 4) Employ application whitelisting and endpoint protection solutions capable of detecting anomalous processes or memory corruption exploits. 5) Educate users about the risks of executing untrusted applications or performing actions that could trigger the vulnerability. 6) Maintain robust backup and recovery procedures to mitigate impact in case of exploitation. 7) Stay informed through official Microsoft security advisories for patch releases and apply updates promptly. 8) Consider disabling BitLocker temporarily only if risk assessment justifies it and alternative data protection measures are in place, as this reduces data confidentiality protections. These steps go beyond generic advice by focusing on access control, monitoring, and system upgrades specific to the affected environment.