# Microarchitectural Data Sampling New class of [[Transient Execution]] attacks discovered in 2019. Notable exploits include [[Fallout]], [[RIDL]], and [[Zombieload]]. ## Wikipedia [page](https://en.wikipedia.org/wiki/Microarchitectural_Data_Sampling) > The Microarchitectural Data Sampling (MDS) vulnerabilities are a set of weaknesses in Intel x86 microprocessors that use hyper-threading, and leak data across protection boundaries that are architecturally supposed to be secure. The attacks exploiting the vulnerabilities have been labeled Fallout, RIDL (Rogue In-Flight Data Load), ZombieLoad.,[2][3][4] and ZombieLoad 2.[5]