“Downfall” bug affects years of Intel CPUs, can leak encryption keys and more

Downfall is a speculative-execution CPU vulnerability disclosed by researcher Moghimi that affects a wide range of Intel processors (Skylake through Tiger Lake / 6th–11th gen), including consumer Core families and Xeon/server chips. Mitigations require microcode/firmware updates (with OS-level options on non-SGX systems), can degrade performance—reportedly up to 50% for Gather-instruction-heavy workloads—and the researcher published a white paper and coordinated disclosure with Intel.