CVE-2025-55330 is a vulnerability identified in Microsoft Windows 11 Version 25H2 (build 10.0.26200.0) that affects the BitLocker full disk encryption feature. The root cause is an improper enforcement of behavioral workflow (CWE-841), which means the system fails to correctly enforce the expected sequence of operations or checks within BitLocker’s security mechanisms. This flaw allows an attacker with physical access to the device to bypass BitLocker protections, potentially gaining unauthorized access to encrypted data without needing any authentication or user interaction. The vulnerability does not impact system availability but severely compromises confidentiality and integrity of the encrypted data. The CVSS 3.1 vector indicates that the attack requires physical access (AV:P), has low attack complexity (AC:L), requires no privileges (PR:N), and no user interaction (UI:N). The scope is unchanged (S:U), but the impact on confidentiality and integrity is high (C:H/I:H), with no impact on availability (A:N). No known exploits have been reported in the wild, and no patches have been released as of the publication date (October 14, 2025). The vulnerability was reserved in August 2025 and published shortly after. This flaw is particularly concerning for organizations relying on BitLocker to protect sensitive data on portable devices, as physical attackers could bypass encryption safeguards. The lack of patches means organizations must rely on compensating controls until a fix is available.

For European organizations, this vulnerability poses a significant risk to the confidentiality and integrity of sensitive data protected by BitLocker on Windows 11 Version 25H2 devices. Organizations in sectors such as finance, healthcare, government, and critical infrastructure that use BitLocker to secure portable devices and laptops are particularly vulnerable to data breaches if devices are lost, stolen, or physically accessed by attackers. The ability to bypass encryption without authentication increases the risk of unauthorized data disclosure and tampering. Although the attack requires physical access, the widespread use of Windows 11 and BitLocker in Europe means the potential attack surface is large. This could lead to regulatory compliance issues under GDPR if personal data is compromised. The vulnerability does not affect system availability, so operational disruption is unlikely, but the breach of confidentiality and integrity could have severe reputational and financial consequences.

Until Microsoft releases a patch, European organizations should implement strict physical security controls to prevent unauthorized access to devices, including secure storage, access restrictions, and surveillance. Employ hardware-based security features such as TPM with PIN or multifactor authentication to strengthen BitLocker protection. Regularly audit and monitor device access logs for suspicious activity. Consider disabling BitLocker suspend or recovery key usage in environments where physical security cannot be guaranteed. Educate employees on the risks of device theft and the importance of reporting lost or stolen devices immediately. Prepare for rapid deployment of patches once available by maintaining an up-to-date asset inventory and patch management process. Additionally, consider using complementary encryption or endpoint detection tools to detect anomalous behavior indicative of exploitation attempts.