CVE-2026-10670 User-triggerable kernel NULL-pointer dereference (DoS) in `k_thread_name_copy()` syscall verifier
Unprivileged user code can crash the Zephyr kernel via a NULL pointer dereference in the thread name copy syscall verifier.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-10670?
CVE-2026-10670 is a medium-severity vulnerability in Zephyrproject Zephyr, published on 14 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The CONFIG_USERSPACE verification handler for the k_thread_name_copy() system call (z_vrfy_k_thread_name_copy() in kernel/thread.c) calls k_object_find() on the caller-supplied thread pointer and then dereferences the returned struct k_object without checking it for NULL. k_object_find() returns NULL whenever the supplied pointer is not a registered (static or dynamic) kernel object.
The pre-fix guard tested thread == NULL instead of ko == NULL, so an unprivileged user-mode thread that invokes k_thread_name_copy() with any non-NULL but unregistered pointer (e.g. an arbitrary address) passes the NULL test, after which the verifier reads ko->type through a NULL pointer.
Because the syscall verifier runs in supervisor mode, this NULL dereference is a kernel-mode fault that halts or reboots the system, allowing untrusted user code to crash the kernel across the userspace security boundary (denial of service). The marshaller passes the thread argument to the verifier without any prior K_SYSCALL_OBJ validation, so the bad pointer reaches the defect directly.
The flaw affects builds with CONFIG_USERSPACE and CONFIG_THREAD_NAME enabled and has been present since the special-case lookup was introduced around v2.0.0; it is present in v4.4.0 and earlier. The fix changes the guard to check the k_object_find() return value (ko == NULL) before dereferencing it.
Weakness: CWE-476
Which versions are affected by CVE-2026-10670?
It affects 1 product.
Products include Zephyrproject Zephyr.
How do I fix CVE-2026-10670?
No fix has been published for CVE-2026-10670 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-10670 being exploited?
There is no known exploitation of CVE-2026-10670 in the wild and no public exploit code.
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Sources
Also known as GHSA-82h2-v4vm-q2g9.