Two important Windows security deadlines are coming up this month — one this Tuesday, one by 24 June. Both affect businesses running Windows PCs and servers.
- Patch Tuesday — 9 June: Microsoft's monthly security update is released this Tuesday. Given the actively exploited Netlogon vulnerability disclosed last month, we recommend applying these updates promptly across all Windows devices, especially servers.
- Secure Boot certificate expiry — 24 June: Security certificates built into Windows since 2011 expire on 24 June 2026. Microsoft has been replacing them automatically via Windows Update, but devices that have not received the update will stop getting early boot-level security protections after that date.
- Who is affected: All businesses running Windows PCs and servers. Devices manufactured since 2024 are likely already updated. Older or unmanaged devices are most at risk of missing the certificate update.
- What the risk is: Missing the Secure Boot certificate update does not stop your computer from working, but it leaves the early startup process unprotected against future threats.
- What to do: Ensure Windows Update is running on all devices. If your IT is managed, ask your provider to confirm the Secure Boot certificate update has been applied across your fleet before 24 June.
If you have any concerns about your update status before the deadline, contact your IT provider now rather than waiting. Sources: Microsoft IT Pro Blog, Malwarebytes