CVE-2026-10667 (GCVE-0-2026-10667)

Vulnerability from cvelistv5 – Published: 2026-07-12 16:16 – Updated: 2026-10-15 22:10
VLAI
Title
SMP use-after-free in Zephyr `CONFIG_USERSPACE` dynamic kernel-object tracking, reachable from unprivileged user threads
Summary
Zephyr's dynamic kernel-object tracking (kernel/userspace/userspace.c, formerly kernel/userspace.c) maintains a doubly-linked list (obj_list) of dynamically allocated kernel objects. Iteration over this list in k_object_wordlist_foreach() was performed under lists_lock using the SAFE iterator (which caches the next node), but list removal and freeing of nodes was performed under different, disjoint spinlocks: objfree_lock in k_object_free() and obj_lock in unref_check(). On an SMP system, while one CPU iterated obj_list under lists_lock, another CPU could unlink and k_free() the dyn_obj node that the iterator had cached as its next pointer, causing the iterator to dereference freed kernel memory (use-after-free / dangling list traversal). All of the racing operations are reachable from unprivileged user-mode threads via system calls: k_object_alloc/k_object_alloc_size and k_object_release drive removals through unref_check() (under obj_lock), while k_thread_abort and thread creation drive the iteration through k_thread_perms_all_clear()/k_thread_perms_inherit() (under lists_lock). A deprivileged user thread on a CONFIG_SMP + CONFIG_USERSPACE build can therefore corrupt the kernel's object-tracking structures across the userspace security boundary, yielding kernel memory corruption (potential privilege escalation) or a kernel crash (denial of service). The fix removes objfree_lock and serializes every obj_list modification under lists_lock, including holding it across find+remove in k_object_free() and around unref_check() in k_thread_perms_clear(). Affects CONFIG_SMP+CONFIG_USERSPACE+CONFIG_DYNAMIC_OBJECTS configurations; the defect dates to the 2019 spinlockification (commit 8a3d57b6cc6, first released in v1.14.0) and shipped through v4.4.0.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
SSVC
Exploitation: poc Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-13 15:49 UTC
CWE
Assigner
zephyr CNA under the mitre root
CNA scorecard B 77/100 over 200 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
zephyrproject zephyr Affected: 1.14.0 , < 4.3.1 (semver)
Affected: 4.4.0 , < 4.4.2 (semver)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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