AMD Releases Updated Zen 3 CPU Microcode (November 2021)
The updated AMD Family 19h "Zen 3" microcode was committed today to linux-firmware.git. Unfortunately, as usual, there isn't any public change-log to note what has changed with this AMD CPU microcode revision.
This update though does come just days after the AMD-SB-1021 security bulletin. That AMD security bulletin for November 2021 noted a wide number of CVEs (including several "high" severity) issues affecting their EPYC processors. Those CVEs included vulnerabilities in the PSP, SMU, and other CPU-related issues.
AMD is releasing new AGESA for mitigating those issues and should be pushed down soon as BIOS updates by various server/motherboard vendors. I'm waiting to hear back if today's CPU microcode update is related to last week's disclosures or if there is anything else of note with today's revision.