Hopefully yes, if it’s proven the vendor knew but released anyway or didn’t disclose.
And all bugs are potentially a security issue.
mitigations=off
Anyone who needs out-of-the-box performance can get it if they're willing to accept out-of-the-box security. Of course that doesn't make these side-channel attacks any less frustrating. For instance the original Meltdown and Spectre attacks were on my mind when I chose to "vote with my dollar" and buy an AMD CPU, only to end up with Zenbleed this year lolWhy do people conveniently forget even fairly recent history is beyond me.
Let's look at a random processor, like, say, the Intel Pentium G3420. A budget CPU released in December 2013 (coming up on its 10th birthday), it's a duo core CPU with a 3.2 GHz clock speed. Now I don't know what your usecase is, not many problems are nicely parallelizable, however at the scale we're talking it doesn't really matter that much. Because 3.2 billion instructions is a really big number. Now don't get me wrong, a million is also a quite sizable number; while 1 dollar won't even buy you a loaf of bread a million dollars will buy you a real fancy house, but a billion goes even beyond that. For example if you live to be 85 years old and from the moment you are born until the moment you pass away you do a thousand calculations per hour, every hour of the day, every day of every year, you will have done 750 million calculations. That's less than a quarter of what that ancient budget CPU does _per second_.
Unfortunately some people, when given access to such power, have a tendency to abuse it. And that's what leads us to things like a chat app taking 9 seconds to launch.
(Though an hardware switch would be better for these.)
The OG transient execution CPU vulnerability, Spectre, works on Intel, AMD, modern ARM-based, and IBM processors.