CVE-2026-12365: zephyrproject zephyr · Use After Free
Affects zephyrproject zephyrSource CVE Database V5
Not known to be exploited · CVSS 5.8 Medium : upgrade to 4.5.0 when convenient.
Data as of 12 Nov 2026, 23:24 UTC
Thin evidence
One scorer or none| CNA (zephyr) | CVSS 3.1 | 5.8 |
|---|
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.5.0
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade zephyrproject zephyr to 4.5.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| zephyrprojectzephyr | Affected
| Fixed in
|
GitHubzephyrpkg:github/zephyrOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in Zephyr version 4.5.0. Users should upgrade to this version or later to remediate the vulnerability. No additional mitigations are required as the fix addresses the concurrency defect directly.
Description
CVE-2026-12365 is a use-after-free vulnerability in the Zephyr project's kernel work queue implementation affecting versions from 2.6.0 up to but not including 4.5.0. The flaw occurs when a delayable work item's timeout handler runs concurrently with a cancellation that does not properly wait for the handler to finish, leading to kernel memory corruption or crash. This is a kernel-internal concurrency defect requiring an SMP build and specific timing conditions. The vulnerability has a medium severity with a CVSS score of 5.8. A fix is available in Zephyr version 4.5.0.