CVE-2026-10682 Out-of-bounds write in Zephyr `log_filter_set` syscall verifier reachable from userspace
An out-of-bounds write in Zephyr's log filter syscall allows unprivileged users to corrupt kernel memory and escalate privileges.
- 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-2026-10682?
CVE-2026-10682 is a medium-severity memory corruption vulnerability in Zephyrproject Zephyr, published on 27 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The userspace verifier z_vrfy_log_filter_set() for the log_filter_set syscall in subsys/logging/log_mgmt.c performed a signed comparison against the int16_t src_id parameter: src_id < (int16_t)log_src_cnt_get(domain_id). Any negative value for src_id (e.g. -1) trivially satisfied this check and was forwarded into z_impl_log_filter_set, where it propagated to filter_set() and ultimately to get_dynamic_filter(), which uses source_id as an unsigned index into the linker-section array &TYPE_SECTION_START(log_dynamic)[source_id].filters.
After implicit conversion through uint32_t, an int16_t -1 becomes 0xFFFFFFFF, indexing log_dynamic far out of bounds and causing the kernel to perform an OOB read and an OOB read-modify-write (LOG_FILTER_SLOT_GET/SET) against memory adjacent to the log_dynamic section.
The written value is a constrained 3-bit log level slot within the targeted 32-bit word, but the target address is attacker-chosen (a small negative offset from log_dynamic) and the write occurs in supervisor mode following a syscall from an unprivileged user thread, providing a kernel memory-corruption / privilege-escalation primitive.
The defect is reachable on any build with CONFIG_USERSPACE=y and CONFIG_LOG_RUNTIME_FILTERING=y. Present from Zephyr v3.3.0 through v4.4.1. The fix replaces the signed bound check with an unsigned comparison: (uint32_t)src_id < log_src_cnt_get(domain_id), which correctly rejects negative inputs.
Weakness: CWE-787
Which versions are affected by CVE-2026-10682?
It affects 1 product.
Products include Zephyrproject Zephyr.
How do I fix CVE-2026-10682?
No fix has been published for CVE-2026-10682 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-10682 being exploited?
There is no known exploitation of CVE-2026-10682 in the wild and no public exploit code.
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Sources
Also known as GHSA-6vqh-mg7h-58qh.