CVE-2025-55333 is a vulnerability identified in Microsoft Windows 11 Version 25H2 (build 10.0.26200.0) affecting the BitLocker full disk encryption feature. The root cause is an incomplete comparison operation within BitLocker’s security logic, classified under CWE-1023 (Incomplete Comparison with Missing Factors). This flaw allows an attacker with physical access to the device to bypass BitLocker’s encryption protections, potentially gaining unauthorized access to encrypted data. The vulnerability does not require any privileges or user interaction, but physical access is mandatory, limiting the attack vector to scenarios where an attacker can directly interact with the hardware. The CVSS v3.1 base score is 6.1 (medium severity), with attack vector marked as physical (AV:P), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N). The impact affects confidentiality and integrity (both high), but not availability. No known exploits have been reported in the wild, and no official patches have been released at the time of publication. The vulnerability’s exploitation could undermine the trust in BitLocker’s encryption, which is widely used to protect sensitive data on Windows devices. Organizations relying on BitLocker for data protection need to be aware of this risk, especially in environments where physical device security cannot be guaranteed. The vulnerability highlights the importance of comprehensive security checks in cryptographic implementations and the risks posed by physical attacks on endpoint encryption.

For European organizations, the impact of CVE-2025-55333 is significant in sectors where BitLocker is deployed to protect sensitive or regulated data, such as finance, healthcare, government, and critical infrastructure. Successful exploitation could lead to unauthorized data disclosure and manipulation, violating data protection regulations like GDPR. The requirement for physical access limits the threat to scenarios involving device theft, loss, or insider threats. However, given the widespread adoption of Windows 11 and BitLocker in Europe, the potential attack surface is large. Organizations with mobile or remote workforce using encrypted laptops are particularly vulnerable. The breach of confidentiality and integrity could result in financial losses, reputational damage, and regulatory penalties. Additionally, the inability to fully trust BitLocker’s encryption could force organizations to reconsider their endpoint encryption strategies, potentially incurring additional costs. The lack of a patch increases the urgency for interim mitigations to reduce exposure until a fix is available.

1. Enforce strict physical security controls to prevent unauthorized access to devices, including secure storage, access logs, and surveillance in sensitive areas. 2. Implement multi-factor authentication for BitLocker, such as TPM with PIN or USB key, to add layers beyond the vulnerable comparison logic. 3. Use complementary encryption or data protection solutions at the application or file level to reduce reliance on full disk encryption alone. 4. Monitor and audit device access and usage patterns to detect suspicious physical access attempts or anomalies. 5. Educate employees on the risks of device theft and the importance of reporting lost or stolen devices immediately. 6. Maintain an inventory of devices running Windows 11 25H2 with BitLocker enabled to prioritize risk assessments. 7. Stay alert for official patches or updates from Microsoft and apply them promptly once available. 8. Consider disabling BitLocker on devices in high-risk physical environments until a patch is released, if feasible. 9. Employ endpoint detection and response (EDR) tools capable of detecting attempts to bypass encryption or tamper with device security. 10. Review and update incident response plans to include scenarios involving physical compromise of encrypted devices.