MEDIUMpublic-safe

CVE-2026-10681

NVD: In Zephyr's userspace dynamic-objects subsystem, thread_idx_alloc() in kernel/userspace/userspace.c allocated a new thread permission index from the global _thread_idx_map[] bitmap without holding lists_lock. NVD: On SMP systems, two user-mode threads invoking the k_object_alloc(K_OBJ_THREAD) syscall concurrently can both observe the same low free bit, perform the same non-atomic RMW to clear it, and return the identical tidx. NVD: The two newly created K_OBJ_THREAD objects are then assigned the same thread_id, so the two user threads alias a single bit position in every kernel object's perms[] bitfield: any subsequent grant of access on a kernel object to one thread is implicitly a...

CVSS
6.5 Severity
MEDIUM EPSS
0.0008 (0) KEV
-

Source-published summary

Possible impact

This medium severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for defensive exposure review.

Affected context

Affected product or version requires source confirmation.

Remediation / advisory

Remediation reference present; patch status requires confirmation in the linked advisory.

Why it matters

This medium severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for defensive exposure review.; CVSS 6.5 (MEDIUM); EPSS percentile 0; not listed in KEV; Remediation reference present; patch status requires confirmation in the linked advisory; sources: NVD, OSV.

What to verify

Confirm affected product/version, vendor advisory, patch or mitigation, and exposure.

Exposure hint

exposure unknown

Impact tags

明示タグなし

Urgency reasons

vendor advisory presentrecent updateremediation reference present

Source-derived note

Summary derived from NVD / OSV description; unsafe procedural detail is not shown.

Redaction metadata

source summary used: True
fallback summary used: False
unsafe procedural detail present: false
raw source displayed: false
public summary redacted: true

Remediation handoff

Public-safe static handoff for human/Codex remediation planning. Scan, patch, external execution, and auto remediation are disabled.

Handoff JSON Handoff Markdown Safe Codex prompt

Safety note

This radar shows source-published defensive context only. Exploit procedures, exploit strings, scanner commands, and auto-remediation are not provided.