Yet another chip flaw allows attackers to steal any data that's recently been accessed by the processor. Almost every Intel chip manufactured since 2011 is vulnerable. The good news is that attackers must be able to run code on the machine, which requires the machine to have already been compromised in some other manner.
Microsoft, Apple, and Google have already issued updates to stop the vulnerability, which takes advantage of Microarchitectural Data Sampling. AWS has also patched their hypervisors and published this Security Release.
Red Hat's YouTube channel has an excellent video detailing the MDS exploit.
Codedamn has a short video demonstrating the attack in action.