CVE-2024-49866 is a race condition vulnerability in the Linux kernel's tracing timerlat component during CPU hotplug processing. The issue occurs because the CPU online processing for osnoise is asynchronous with the offline processing, which can cause the timerlat/1 thread to be scheduled on a CPU that has already been taken offline, leading to timer corruption and potential kernel instability. The flaw has been fixed by skipping online processing if the CPU is already offline.