Microsoft and Google just announced a new CPU speculative execution flaw that’s similar to Spectre and Meltdown: Speculative Store Bypass.
As with Spectre and Meltdown, almost all CPU chips made in the last ten years are affected by this issue.
Bruce Schneier thinks there are more speculative execution flaws coming. And he’s probably right.
Intel has decided not to produce Spectre microcode updates for some of the oldest of their affected CPUs, leaving most Core 2 chips without any hope of a Spectre fix. As for first generation CPUs, some will get updates, and some will not. Microcode updates for all CPUs from generation 2 through generation 8 have already been released.
Not sure whether your computer is affected by Spectre? If you’re running Windows, Gibson Research’s free InSpectre tool will tell you what you need to know. Looking for a Spectre BIOS update for your computer? PCWorld’s guide is a good starting point.
Intel has produced new microcode for most Spectre-affected CPUs, but some manufacturers have yet to provide corresponding BIOS updates for all affected motherboards. They may have decided not to bother developing updates for older motherboards. That’s a potential problem for millions of computers running older CPUs that are new enough to be vulnerable to Spectre. If the manufacturer hasn’t released a BIOS update with Spectre fixes for your motherboard, consider contacting them to find out when that’s going to happen.
Update 2018May24: I contacted Asus about a particular desktop PC I happen to own, and was told that “details on whether or not there will be a Spectre BIOS update for the <model> is [sic] currently not available.” That doesn’t sound very encouraging. It feels like they’re waiting to see how many complaints they get before committing resources to developing patches.