CVE-2026-12366

Zephyr's dynamic kernel-object disposal path unrefcheck in kernel/userspace/userspace.c frees an object's storage kfreedyn-data once its reference count reaches zero, after running a per-object-type cleanup. The cleanup switch handled only KOBJMSGQ and KOBJSTACK; there was no KOBJTIMER case. A...

CVE-2026-10681

In Zephyr's userspace dynamic-objects subsystem, threadidxalloc in kernel/userspace/userspace.c allocated a new thread permission index from the global threadidxmap bitmap without holding listslock. On SMP systems, two user-mode threads invoking the kobjectallocKOBJTHREAD syscall concurrently can...

CVE-2026-10681 SMP race in `thread_idx_alloc()` lets concurrent `k_object_alloc(K_OBJ_THREAD)` callers share a kernel-object permission slot

In Zephyr's userspace dynamic-objects subsystem, threadidxalloc in kernel/userspace/userspace.c allocated a new thread permission index from the global threadidxmap bitmap without holding listslock. On SMP systems, two user-mode threads invoking the kobjectallocKOBJTHREAD syscall concurrently can...

CVE-2026-10681

CVE-2026-10681 overview (Zephyr) : In the userspace dynamic-objects subsystem, thread_idx_alloc() reads and clears the global _thread_idx_map[] bitmap without holding lists_lock. On SMP systems, concurrent k_object_alloc(K_OBJ_THREAD) calls can observe the same free bit, perform a non-atomic RMW,...

CVE-2026-10681 SMP race in `thread_idx_alloc()` lets concurrent `k_object_alloc(K_OBJ_THREAD)` callers share a kernel-object permission slot

In Zephyr's userspace dynamic-objects subsystem, threadidxalloc in kernel/userspace/userspace.c allocated a new thread permission index from the global threadidxmap bitmap without holding listslock. On SMP systems, two user-mode threads invoking the kobjectallocKOBJTHREAD syscall concurrently can...

PT-2026-64764

Name of the Vulnerable Software and Affected Versions Zephyr versions prior to 4.4.1 Description In the userspace dynamic-objects subsystem, the thread idx alloc function in kernel/userspace/userspace.c allocates a new thread permission index from the global thread idx map bitmap without holding...

CVE-2026-10667 SMP use-after-free in Zephyr `CONFIG_USERSPACE` dynamic kernel-object tracking, reachable from unprivileged user threads

Zephyr's dynamic kernel-object tracking kernel/userspace/userspace.c, formerly kernel/userspace.c maintains a doubly-linked list objlist of dynamically allocated kernel objects. Iteration over this list in kobjectwordlistforeach was performed under listslock using the SAFE iterator which caches t...

CVE-2026-10667 SMP use-after-free in Zephyr `CONFIG_USERSPACE` dynamic kernel-object tracking, reachable from unprivileged user threads

Zephyr's dynamic kernel-object tracking kernel/userspace/userspace.c, formerly kernel/userspace.c maintains a doubly-linked list objlist of dynamically allocated kernel objects. Iteration over this list in kobjectwordlistforeach was performed under listslock using the SAFE iterator which caches t...

CVE-2026-10667 SMP use-after-free in Zephyr `CONFIG_USERSPACE` dynamic kernel-object tracking, reachable from unprivileged user threads

Zephyr's dynamic kernel-object tracking kernel/userspace/userspace.c, formerly kernel/userspace.c maintains a doubly-linked list objlist of dynamically allocated kernel objects. Iteration over this list in kobjectwordlistforeach was performed under listslock using the SAFE iterator which caches t...