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Microsoft released its June 2026 Patch Tuesday security update yesterday and this one is historically large.
June 2026 marks the largest single Patch Tuesday release in the program's history, addressing 200 security vulnerabilities across Windows, Office, Azure, Exchange, Hyper-V, and related products. For small businesses in Massachusetts that rely on Windows devices, there are several things worth understanding before the end of the week.
At Ekaru, we provide managed IT services for small businesses across greater Boston. Staying ahead of security patches is one of the most important things a small business IT support provider can do for its clients. Here is what matters most this month.
The Secure Boot Deadline Is 16 Days Away
Before diving into this month's new vulnerabilities, the most important reminder for any small business still running Windows devices is this: the Secure Boot certificate expiration deadline is June 26, 2026, just 14 days away.
If your devices have not yet received the May 2026 update, June's Patch Tuesday is your final scheduled opportunity to get compliant before that deadline. Boot-level malware will be impossible to detect or remove with standard tools on devices that miss this window. The June 26 deadline is absolute and non-negotiable.
If Ekaru manages your IT, your devices should already be tracked. If you are not sure, run Windows Update today and confirm KB5089549 from May is installed alongside this month's updates. This is exactly the kind of proactive IT management that protects small businesses in the Boston area from preventable security incidents.
What Microsoft Fixed in June 2026
Of the 200 Windows security updates addressed this month, 33 are rated Critical, 166 are rated Important, and one is rated Moderate. Twenty-eight of the critical flaws are remote code execution vulnerabilities, four are elevation of privilege issues, and one is an information disclosure flaw.
Here are the Microsoft security patches small businesses should understand:
Windows Kernel Remote Code Execution
This is the most serious vulnerability management concern in this month's release. A remote unauthenticated attacker can run code at SYSTEM level with no user interaction, through a flaw in how the kernel handles TCP/IP. In plain English, an attacker on the internet could potentially take full control of an unpatched Windows device without any employee clicking anything. This one alone makes June's Windows 11 update urgent for every business.
Windows BitLocker Security Bypass
This vulnerability allows an attacker with physical access to a device to bypass BitLocker's full-disk encryption and access the data on it. For small businesses that rely on BitLocker to protect laptops, particularly important if a device is ever lost or stolen, this fix is essential. This patch closes a significant gap in your endpoint security protection.
Windows Denial of Service
This vulnerability is related to an attack technique that can affect web servers and knock them offline in seconds. For businesses running any web-facing services or applications on Windows Server, this is worth prioritizing.
Remote Desktop Services
Remote Desktop Client received the most concentrated cluster of critical patches this month with 11 total fixes. If your team uses Remote Desktop to connect to office computers or servers remotely, this month's security patch is non-negotiable.
What You Should Do Today
The steps are the same as every month but this month they are more urgent than usual given the severity of the vulnerabilities and the approaching Secure Boot deadline.
Go to Settings, select Windows Update, and check for updates. Install everything available and then do a full Restart, not just Shut Down. The restart is what completes the installation process.
If any devices in your office show errors during the update process, contact your IT support provider before the end of the week. With the June 26 Secure Boot deadline approaching, there is no comfortable buffer left. Unpatched systems remain one of the leading entry points for ransomware attacks targeting small businesses.
Ekaru Helps You Stay Ahead
The Ekaru team provides managed IT services in Boston and monitors Windows updates for small businesses across Westford, Acton, Chelmsford, Lowell, and the greater Boston area. Our patch management services include security update tracking, compliance monitoring, and device management to catch update failures before they become problems.
Not sure whether your business is protected? A free IT assessment is the fastest way to find out.