Zen 5 is AMD's first architecture utterly immune to the Inception vulnerability since Zen 3 requires no microcode or software-based security mitigations. Phoronix tested the Zen 5-based Ryzen 9 9950X with all security mitigations on and off in Linux (for other vulnerabilities) to see if there is any performance variance.
Phoronix discovered that Zen 5 features built-in/native mitigation of the Inception vulnerability. Inception is a speculative side-channel attack discovered last year, affecting Zen 3 and Zen 4. Inception enables attackers to access information stored on system DRAM, leading to the leakage of potentially privileged data.
