Yesterday we reported on Windows 11 24H2 Defender security update as part of the August 2025 Patch Tuesday cycle to counter the Lumma stealer and similar malware and exploits. The cumulative package KB5063878 included in the update caused SSDs to fail, possibly corrupting data. Community testing has since identified a reproducible pattern in which certain SSDs, when running sustained sequential writes of approximately 50 GB, become inaccessible and display unreadable SMART telemetry. Additionally, under 60% or higher controller load, most of the SSDs failed. This indicates that Microsoft's patch and some controller firmware may be disagreeing in the logic of operations. However, Phison, as one of the makers of the impacted controllers, has decided to be vocal about it and informed Tom's Hardware that the company is actively looking into the issue.

Phison for Tom's Hardware Phison has recently been made aware of the industry-wide effects of the 'KB5063878' and 'KB5062660' updates on Windows 11 that potentially impacted several storage devices, including some supported by Phison. We understand the disruption this may have caused and promptly engaged industry stakeholders. We are steadfast in our commitment to product integrity and the success of our partners and end users. At this time, the controllers that may have been affected are under review and we are working with partners. We will continue to provide updates and advisories to partners who may have been impacted to provide support and ensure any applicable remediation.