Medium · published May 22, 2018
CVSS calls it medium at 5.5. It sits in the 99.1th percentile for exploit probability.
Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addresses of all prior memory writes are known may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka Speculative Store Bypass (SSB), Variant 4.