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PayPalBack in August 2024, Microsoft released an update for various versions of Windows including Windows 10 and 11 that broke dual-booting with Linux on some setups. They've now finally solved it. Only took them 9 months.
The issue came from a Windows security update, something that was not supposed to affect systems where it detected a dual-boot but Microsoft failed on that causing problems for many to be unable to boot into their Linux installs.
From Microsoft:
After installing the August 2024 Windows security update, (KB5041160) or the August 2024 preview update, you might face issues with booting Linux if you have enabled the dual-boot setup for Windows and Linux in your device. Resulting from this issue, your device might fail to boot Linux and show the error message “Verifying shim SBAT data failed: Security Policy Violation. Something has gone seriously wrong: SBAT self-check failed: Security Policy Violation.”
The August 2024 Windows security and preview updates apply a Secure Boot Advanced Targeting (SBAT) setting to devices that run Windows to block old, vulnerable boot managers. This SBAT update will not be applied to devices where dual booting is detected. On some devices, the dual-boot detection did not detect some customized methods of dual-booting and applied the SBAT value when it should not have been applied.
Microsoft did tweak this so that from September 19, 2024 and later updates did not do this automatically, but the damage was already done.
As of the May 13, 2025 update for Windows, this has now been solved. As the changelog notes:
Article taken from GamingOnLinux.com.
- [Secure Boot Advanced Targeting (SBAT) and Linux Extensible Firmware Interface (EFI)] This update applies improvements to SBAT for the detection of Linux systems.
You can also find comments for this article on social media: 
tfk 8 hours ago
Minux 8 hours ago
"It's time for some layoffs."
benstor214 4 hours ago
There was another obvious fix available from the beginning. Not running Windows.
Windows turned out to be a very effective virus on Linux systems...
elmapul 4 hours ago
Hooly 4 hours ago
Microsoft had already given them a 6 month grace period when the vulnerability was made public before blocking the vulnerable bootloader version.
Blocking that bootloader version after the grace period despite not being updated in any distro yet was the responsible thing to do, and Linux distros were absolutely lazy to not give this issue the appropriate urgency.
Last edited by Hooly on 19 May 2025 at 3:27 pm UTC
Kimyrielle 3 hours ago
There was another obvious fix available from the beginning. Not running Windows.
At least not handing Microsoft control over your computer by enabling Secure Boot. But I really wonder for how much longer they will even allow it to be disabled.
F.Ultra 50 minutes ago
To be fair here, while Microsoft dragged their feet for 9 months to improve their dual-boot detection, Linux distros dragged their feet to update the vulnerable (that is why it was blocklisted via dbx) bootloader for over 12 months.
Not true, the vulnerable bootloader was fixed ages ago, the thing was though that the blacklisted key was not in the bootloader package but in the shim and since only the bootloader was changed the shim was left untouched so when MS decided to block the old bootloader they instead blocked the shim (that was not vulnerable).
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