Take action: Mitigation guidance updated with a new script for CVE-2026-45585

Updated June 9, 2026: This message has been updated to reflect the availability of the June 2026 security update, which addresses CVE‑2026‑45585. If you have applied the temporary mitigations documented prior to this update’s release, you do not need to revert it once you install the update. Microsoft has updated the mitigation guidance in CVE-2026-45585, a Windows BitLocker security feature bypass vulnerability. The June 2026 security update that addresses this vulnerability is now available. Note that a limited set of Windows versions are affected: Windows 11, versions 26H1, 25H2, and 24H2, and Windows Server 2025. When will this happen: The June 2026 security update and the updated mitigation guidance are available now. How this will affect your organization: Microsoft recommends applying the June 2026 security update to address this vulnerability. Windows devices that use BitLocker may be exposed if mitigations are not applied. Organizational environments that previously implemented the manual mitigation steps or the mitigation script do not need to take additional action, and the previously applied mitigation does not need to be reverted.   What you need to do to prepare: Organizational environments using BitLocker on affected Windows versions should review the updated guidance in the Microsoft Security Update Guide to determine the appropriate action for their environment. Additional information:          CVE-2026-45585: Windows BitLocker Security Feature Bypass Vulnerability