Linux Kernel CVE-2026-53282

The affected subsystem is the x86 kexec implementation in the Linux kernel (CPE: cpe:2.3:a:linux:linux). kexec is a Linux system call enabling one kernel to directly boot another without passing through firmware - used for fast reboots, kdump crash capture, and live patching. The 'purgatory' is a small, self-contained blob of code that executes in the handoff window between the old and new kernel, verifying checksums before transferring control. kjump (kernel jump) is a related execution path for in-place jumps. A prior kernel commit correctly fixed the kjump path but eliminated a stack push that, while unused in the non-kjump path, was expected by the kexec-tools purgatory: it reads the word above its own stack top looking for a kjump return address even when one was never set. With that word now potentially unmapped or corrupt, the access faults. Although CWE is formally unassigned, this is effectively a missing stack-frame initialization - a regression in the stack-discipline logic of purgatory entry.