In this "new" flaw, called BranchScope:
"
an attacker primes the PHT and running branch instructions so that the PHT will always assume a particular branch is taken or not taken. The victim code then runs and makes a branch, which is potentially disturbing the PHT. The attacker then runs more branch instructions of its own to detect that disturbance to the PHT; the attacker knows that some branches should be predicted in a particular direction and tests to see if the victim's code has changed that prediction.".
https://arstechnica.com/gadgets/2018...ction-attacks/
The researchers aren't sure how widespread BranchScope will be, but just like with Spectre, it still requires the attacker to be able to execute code on the victim's computer. As many specialists have said, it could take months or even years to fully discover and patch the bugs associated with speculative execution.