Security researchers have uncovered a new variant of the Spectre v2 vulnerability dubbed Branch Target Reuse (BTR), affecting processors from Intel, AMD, and Arm. The flaw targets just-in-time (JIT) compilers used within operating system kernels, web browsers, and language runtimes. Attackers can exploit stale indirect branch prediction entries to speculatively execute code and read sensitive data from system memory. Researchers successfully built a Linux kernel exploit utilizing BTR to leak sensitive information, including a root password hash. While hardware vendors argue that existing Spectre v2 software mitigations like IBPB help guard against BTR, software developers are actively issuing specific patches.

Full report : New Spectre v2 Variant ‘Branch Target Reuse’ Exposes Intel, AMD, and Arm CPUs to Data Leaks.