TL;DR Researchers at VUSec have published full details and proof-of-concept code for Branch Target Reuse (BTR), a new Spectre-v2 attack on just-in-time (JIT) compilers. Their end-to-end exploit leaked the Linux root password hash from kernel memory on modern Intel CPUs, bypassing all enabled mitigations. The Linux kernel has patched the issue under CVE-2026-64507 and CVE-2026-64508. Why the Branch Target Reuse Attack Matters…