Does anyone remember Meltdown and Spectre? These vulnerabilities were discovered in June and July 2017 and publicly documented in early 2018. As a result, countermeasures have been taken by software manufacturers for both operating systems and applications, some of which also lead to reduced performance.
As reported on https://www.ncsc.admin.ch/retbleed-en, researchers of the ETH Zürich now discovered a vulnerability in one of the counter measures – retpoline – affecting CPUs by Intel and AMD which got the name “Retbleed” (CVE-2022-29900, CVE-2022-29901). Also see the description at https://comsec.ethz.ch/research/microarch/retbleed/.