impact

The expiration date of the original Microsoft Secure Boot KEK certificate is June 24, 2026. Microsoft held a live "Ask Microsoft Anything" session on June 4 to address concerns regarding this deadline. The expiration affects the KEK key, while the DB key remains valid until October. After June 24, Microsoft will not be able to sign new DBX payloads, which are necessary for revoking compromised bootloaders. Devices without the new KEK may miss future revocations, leading to decreased security but will not stop booting immediately. The June Patch Tuesday update is expected to classify most systems as high confidence. IT administrators are advised to use the Intune monitoring report for device status and updates. Devices in a "temporarily paused" status require OEM firmware updates. Administrators should not delay manual rollouts for devices outside the high confidence classification. Secure Boot must be enabled to update certificates, and re-enabling it later can pose risks. Older models may receive high confidence classification faster than newer ones due to statistical requirements. In PXE boot environments, caution is needed when updating bootloaders. The Secure Boot update mechanism is consistent across Windows 10 and 11, and event logs are important diagnostic tools. Key event log entries include 1801, 1802, and 1803, which indicate various device statuses and issues. Microsoft provides resources at aka.ms/GetSecureBoot for further guidance.