Researchers from two universities have discovered several new variants of Spectre exploits that affect all modern processors from AMD and Intel with micro-op caches. Existing Spectre mitigations do not protect the CPUs against potential attacks that use these vulnerabilities. Meanwhile, researchers believe that mitigating these vulnerabilities will cause more significant performance penalties than the fixes for previous types of Spectre exploits. However, it remains unknown how easy these vulnerabilities are to exploit in the real world, so the danger may be limited to directed attacks.
