Maybe I'm using big words I don't understand. What is it that Lenovo and such are distributing as part of this? I know they're labeled as BIOS updates but I assumed it's more than that since the BIOS is a different component.
EDIT: So looking into it, it seems that CPU microcode is indeed the firmware, and I presume that the firmware is where a fix such as the one released here would be.
Somebody mentioned a Lenovo update elsewhere in comments. The recent ME updates required an update from Lenovo. I assumed the same would apply here but thankfully not. I wonder why the OS can't update ME firmware the same way.
Updated processor microcode has to be loaded to the processor on every boot, and this can be done either by the system BIOS/firmware or by the OS (or both).
EDIT: So looking into it, it seems that CPU microcode is indeed the firmware, and I presume that the firmware is where a fix such as the one released here would be.
Somebody mentioned a Lenovo update elsewhere in comments. The recent ME updates required an update from Lenovo. I assumed the same would apply here but thankfully not. I wonder why the OS can't update ME firmware the same way.