01 Record
CVE-2026-9728
TOCTOU race in mbox_send syscall verifier allows userspace to leak kernel memory
MediumPUBLISHEDCNA: zephyr
CNA base score6.4 CVSS v3.xCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:L
02 Description
TOCTOU race in mbox_send syscall verifier allows userspace to leak kernel memory
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.11% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 1.1% of scored records. A rank, not a probability.
- NVD base score
- 6.4 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:L
- NVD analysis status
- Awaiting Analysis. NVD last modified this record on 2026-10-12.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-08-24 14:28Z2 MO AGO
- Last updated
- 2026-08-25 19:06Z2 MO AGO
- Reserved
- 2026-05-27
- Assigning CNA
- zephyr
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.4)
- CNA CVSS vector
- CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:L
- Weaknesses
- CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionBase
- Data version
- 5.2
- Document digest
- 9f7f521b037ae58acc4412557a0b951881e22d807acc42f2830e785863f39e31
05 Affected products
VendorProductVersionsPlatforms
06 References
- github.comFix commithttps://github.com/zephyrproject-rtos/zephyr/commit/ab35eaccec5976f05c196f176d0c32885754496f
- github.comGHSA-47q2-w832-7w67https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-47q2-w832-7w67