Western Digital SanDisk X300, X300s, X400, and X600 devices: A vulnerability in the wear-leveling algorithm of the drive may cause cryptographically sensitive parameters (such as data encryption keys) to remain on the drive media after their intended erasure.
https://www.westerndigital.com/support/productsecurity/wdc-19007-sandisk-x300-x400-sata-s
https://www.westerndigital.com/support/productsecurity/wdc-19006-sandisk-x600-sata-ssd