In mid-October 2025, engineers at Meta stumbled upon an anomalous problem with the RDSEED instruction in processors based on AMD's Zen 5 architecture. When this instruction is executed, there's a possibility that it may erroneously return a value of 0 and still indicate a successful operation. This error has a detrimental impact on the dependability of random number generation. Given its potential to compromise system confidentiality and data integrity, the vulnerability has been classified as high-severity. It's important to note that only the 16-bit and 32-bit iterations of the RDSEED instruction are susceptible to this issue, whereas the 64-bit version operates normally without any such risk. AMD has officially recognized this flaw and is set to address it through a microcode update. On November 14, the EPYC 9005 series processors will be the initial recipients of the AGESA firmware update. The Ryzen 9000 series and Ryzen AI 300 series are anticipated to get their updates by the end of November. Meanwhile, the EPYC Embedded 9005 and EPYC Embedded 4005 series are projected to roll out patches to rectify the issue in January 2026. Prior to the release of these corrective updates, AMD advises developers to give precedence to utilizing the 64-bit RDSEED instruction or to disable the instruction forms that are affected by the vulnerability.