Microsoft's June Patch Tuesday lands tomorrow, June 9. This month's update is particularly significant: it addresses actively exploited vulnerabilities and is the final opportunity to complete the Secure Boot certificate transition before a hard deadline of June 26.

• Patch Tuesday – June 9, 2026: Expected to address 60–90 vulnerabilities, including actively exploited flaws in Windows Netlogon and Microsoft Defender. Updates will be distributed via Windows Update from approximately 3:00 AM AEST on June 10.
• Secure Boot Certificate Transition – deadline June 26, 2026: The Secure Boot certificates shipped with Windows since 2011 are expiring. Microsoft is replacing them with new 2023-dated certificates via this month's patch. Windows 11 PCs and Windows Servers that are not updated before June 26 will stop receiving boot-level security updates and malware blacklist (DBX revocation) updates going forward — permanently degrading startup security.
• What this means in practice: Affected systems will continue to boot and run normally after the deadline, but will become more vulnerable to bootkit and firmware-level attacks over time as no further Secure Boot protection updates will be applied.

We recommend scheduling Windows updates for the evening of June 9 or morning of June 10 (AEST). If OzComm manages your devices, we will handle this as part of your regular patch cycle — no action is required on your part. If you manage your own devices, please ensure Windows Update runs before June 26.