Windows and Linux owners must act before June 24, when three Microsoft‑signed certificates that underpin Secure Boot will expire. Those keys verify every firmware and bootloader component, blocking UEFI‑level bootkits that can survive OS reinstalls. Without an update, systems remain operational but lose cryptographic protection against newly discovered threats like the 2023 Logo Fail bug. Enterprise admins should schedule the rollout across fleets promptly.

Secure Boot, introduced by Microsoft after early 2000s bootkit scares, creates a chain of trust from the motherboard vendor to the OS. When any link lacks a valid signature, the machine refuses to start. The upcoming key refresh replaces three 2011 signatures with 2023 versions, and Linux distributors are rolling out matching “shims” to keep the Linux boot path trusted.

Users can verify their key status via Windows Security → Device Security → Secure Boot; a green check confirms the update. Most PCs receive the new certificates automatically through regular Patch Tuesday releases, but older hardware may need manual intervention. Linux users should wait for shim updates before applying any BIOS flash, ensuring the refreshed keys protect against future UEFI attacks. Failure to update leaves machines exposed to persistent firmware compromises.