CVE Explorer
CVE-2026-10681
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.
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.
The two newly created K_OBJ_THREAD objects are then assigned the same th
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","defaultStatus":"unaffected","packageName":"zephyr","product":"zephyr","programFiles":["kernel/userspace/userspace.c"],"vendor":"zephyrproject","versions":[{"lessThan":"4.5.0","status":"affected","version":"2.0.0","versionType":"semver"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:4c0ab9cc13e0dca6b0c936786f5b32dbccd077e6a1bdeac7549e8967a2e75a95 · sha256:3a56326d7bacf069… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"baseScore":6.5,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:4c0ab9cc13e0dca6b0c936786f5b32dbccd077e6a1bdeac7549e8967a2e75a95 · sha256:3a56326d7bacf069… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-362","description":"race","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:4c0ab9cc13e0dca6b0c936786f5b32dbccd077e6a1bdeac7549e8967a2e75a95 · sha256:3a56326d7bacf069… · /containers/cna/problemTypes/0/descriptions/0
Source references
2 source assertions{"name":"Fix commit","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/862ea2fbbeb2ccdf8ff994b03e2e3b4405f2c37d"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4c0ab9cc13e0dca6b0c936786f5b32dbccd077e6a1bdeac7549e8967a2e75a95 · sha256:3a56326d7bacf069… · /containers/cna/references/0
{"name":"GHSA-j693-5rh5-8g8h","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j693-5rh5-8g8h"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4c0ab9cc13e0dca6b0c936786f5b32dbccd077e6a1bdeac7549e8967a2e75a95 · sha256:3a56326d7bacf069… · /containers/cna/references/1
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.