CVE-2026-9728

The userspace syscall verifier zvrfymboxsend in drivers/mbox/mboxhandlers.c validated the nested msg-data/msg-size fields by reading them directly out of live userspace memory, and then forwarded the original, still-mutable userspace struct mboxmsg pointer to zimplmboxsend and the underlying...

CVE-2026-9728

CVE-2026-9728 is a time-of-check/time-of-use (TOCTOU) race condition in the Zephyr RTOS userspace mailbox subsystem. The syscall verifier z_vrfy_mbox_send() in drivers/mbox/mbox_handlers.c validates msg->data/msg->size by reading them directly from live userspace memory, then forwards the o...