On January 8th Intel released new Linux Processor microcode data files that can be used to mitigate the Spectre and and Meltdown vulnerabilities in Intel CPUs. Using microcode files, an operating system can fix known bugs in Intel CPU without having to perform a BIOS update on the computer.

According to the Intel microcode download page, this release is available for 40 different versions of Linux and valid for 2,371 Intel processors all the way down to the 150 mhz Pentium Processor from 1995.

Update 1/11/18 10:45PM EST:

As pointed out in a comment to this article, this microcode release only fixes issues in certain processors.  Below are the list of processors from the release notes that received updates.

Based on information found here and on Intel’s site, the first column is processor model, the second column is the abbreviation from the release notes, and the third is the new revision numbers from the release notes. 

Another reader pointed out that the numbers in parenthesis coincide with the CPUs family, model, and stepping. The format is (family-model-stepping:unknown) with the values being in hexadecimal. You can find the values associated with a particular processor by looking it up on cpu-world.com. We are still unsure what the value after the colon stands for.

For example, if you look up the Haswell processor that has an identifier of (06-3c-03:32) at cpu-world.com, you will see that the information on the site matches the identifier listed in the release notes.

Processor Model Abbreviated Model Revision
IvyTown IVT C0 (06-3e-04:ed) 428->42a
Skylake SKL-U/Y D0 (06-4e-03:c0)…