Systems with microprocessors utilizing speculative execution may allow unauthorized disclosure of information to an attacker with local user access via a side-channel attack on the directional branch predictor, as demonstrated by a pattern history table (PHT), aka BranchScope.
celeron_n
CVE-2018-3640
Systems with microprocessors utilizing speculative execution and that perform speculative reads of system registers may allow unauthorized disclosure of system parameters to an attacker with local user access via a side-channel analysis, aka Rogue System Register Read (RSRE), Variant 3a.