Facepalm: Microsoft's August Security Update Breaks Dual Booting Windows And Linux PCs

Microsoft’s latest set of updates delivered during patch Tuesday is causing headaches for users who are dual booting Linux alongside Windows. One of the updates issued was supposed to address a vulnerability found in the GRUB2 boot loader used by several versions of Linux, which could allow attackers to bypass secure boot. Now, several users running a dual boot configuration are reporting not being able to boot their machines.

After applying the update, users got a rather ominous error message when trying to boot into their Linux installs, which says “Verifying shim SBAT data failed: Security Policy Violation. Something has gone seriously wrong: SBAT self-check failed: Security Policy Violation.” This has left users scrambling to try and find their own solution so they can get back into their systems.


One of the more frustrating aspects of this situation is that Microsoft’s own documentation states that “the SBAT value is not applied to dual-boot systems that boot both Windows and Linux and should not affect these systems.” Except, this is exactly what’s happening, leaving users in a difficult position.

Updates that break things the way this one has, especially after the software maker explicitly states that it won’t, have to be some of the worst. All it does is encourage users to avoid or disregard updates in the future over concerns that something like this can happen again.

In a computing landscape full of evolving attacks, it’s important for users to keep their systems up to date. However, events such as this one make this message a tough one to buy into for users that rightfully feel burned.