CVE-2026-43274

A flaw was found in the Linux kernel's mailbox subsystem, specifically within the mchp-ipc-sbi component. This vulnerability involves an out-of-bounds access in the `mchp_ipc_get_cluster_aggr_irq()` function. The `cluster_cfg` array, which holds per-CPU configuration structures, was incorrectly indexed using `hartid`, which could exceed the array's bounds. This issue can lead to memory corruption within the kernel.