reads of control registers; and , which leaks TSC_AUX register values. Mitigations include microcode updates, Linux kernel patches (tsa= tunable), and optional use of the VERW instruction--albeit with potential performance costs.

In September 2025, researchers at ETH Zurich disclosed VMScape , a Spectre-BTI-style transient execution attack that exploits incomplete isolation of the branch predictor between guest virtual machines and host user-space