The recent Windows 11 security update didn't cause those SSD failures, according to Microsoft (via BleepingComputer). But the root cause is still unknown.

Users began reporting their SSDs and HDDs getting bricked soon after installing a Windows update (KB5063878), released by Microsoft on Aug. 12. The issue was first noticed by Japanese users who reported failed and corrupted drives when working with large files or lots of files on SSDs that were over 60 percent full and had the new update installed. Users reported problems with SSD drives from brands including Corsair, Phison, Fikwot, Maxio, and others.

Microsoft investigated the issue and said they were unable to reproduce the issue, finding no link between between the Windows 11 update and the bricked drives. "After thorough investigation, Microsoft has found no connection between the August 2025 Windows security update and the types of hard drive failures reported on social media," said Microsoft said in an update to the service alert reported by Bleeping Computer.

Microsoft worked with controller-maker Phison to investigate why SSDs with their chips failed. Phison also said it was unable to reproduce any issues, but "continues to closely monitor the situation in collaboration with our industry partners," in a statement to Neowin.

Until the root cause is determined, Phison advised users to use a heatsink or thermal pad to prevent the device from overheating during long, power-heavy sessions. Additionally, a Phison spokesperson told BleepingComputer that users with over 60 percent storage used should "avoid downloading, copying, or writing large files" that are in the tens of gigabytes.