"When Spectre and Meltdown hit just after New Years, it kicked off a flurry of responses from companies like Intel, AMD, ARM, and Microsoft. Patching the flaws, which exploit flaws in branch prediction and speculative execution, has taken several months, with some high-profile failures: Intel had to yank Spectre patches for certain older systems after it became clear they were causing frequent reboots. Fixes resumed rolling out some weeks later, with plans to patch chips as far back as 2007. Those plans have now been canceled.
Previously, we expected Intel would patch Bloomfield (45nm, Core i7), Clarksfield (45nm mobile Core i7), Jasper Forest (45nm Xeon), Penryn (45nm mobile Core 2 Duo), Yorkfield (45nm Core 2 Quad), and Wolfdale (45nm desktop Core 2 Duo). Intel’s SoFIA line of processors, some of which are still sold today, was also set to be updated as well. None of those updates, however, are going to happen."
That is very interesting. Because while you may not have a good way to litigate a flaw they did not know about. It was announced they would fix it. So anyone who bought say a 7700k or 8700k or other 7th or 8th gen chip believing it would get patched, because that is what they said. I would think now has pretty solid grounds to demand a refund. There is huge difference between knowing and not knowing something you are selling is a problem. I will sure bet this isn't the last we here of this.
So apparently most of the more recent CPUs are slated to get updated.
This is the official list of what is and isn't getting updated as of 4/2/18: