It is... somewhat significant. If i recall correctly, you need to generate two large prime numbers to get a key. There are already several caveats for the prim

It is... somewhat significant. If i recall correctly, you need to generate two large prime numbers to get a key. There are already several caveats for the prime generation, so you cannot just take any two primes that are big enough. So for a proper key generation, you generate a lot of random numbers, verify that they are prime and that they are "proper" for RSA. This discovery "just" means that there are some additional steps for verifying the properness of the prime, that every RSA implementor has to add. So for mitigation, there is work to do for implementors, but similar work has been necessary before... Of course, this might have been used to generate backdoorable RSA keys, and giving them to people without their knowledge. If that happened, this issue becomes... more significant for all that have been backdoored.