---
title: "CVE-2026-16513: Zephyr RTIO - Broken Access Control"
description: "Zephyr RTIO subsystem with CONFIG_USERSPACE and CONFIG_RTIO contains a write-what-where vulnerability caused by missing K_SYSCALL_MEMORY_WRITE check on handle out-parameter in z_vrfy_rtio_sqe_copy_in_get_handles(), letting unprivileged user-mode threads write arbitrary kernel memory pointers, exploit requires user-mode thread with RTIO kernel object."
url: https://panop.io/threat-heartbeat/CVE-2026-16513/
---

# CVE-2026-16513 Zephyr RTIO - Broken Access Control

Zephyr RTIO subsystem with CONFIG\_USERSPACE and CONFIG\_RTIO contains a write-what-where vulnerability caused by missing K\_SYSCALL\_MEMORY\_WRITE check on handle out-parameter in z\_vrfy\_rtio\_sqe\_copy\_in\_get\_handles(), letting unprivileged user-mode threads write arbitrary kernel memory pointers, exploit requires user-mode thread with RTIO kernel object.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.11% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-16513)

## Details

Type

Broken Access Control

Impact

Privilege Escalation, Denial Of Service, Data Tampering

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

28 September 2026

Updated

15 October 2026

Weakness

[CWE-787](https://cwe.mitre.org/data/definitions/787.html)

## Vendor fix

Update to a version including the fix adding K\_SYSCALL\_MEMORY\_WRITE checks on output parameters or latest available version.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-16513](https://nvd.nist.gov/vuln/detail/CVE-2026-16513)
- [https://github.com/zephyrproject-rtos/zephyr/commit/95c355c425763fbe5e735b9ef54dacce2c4ce21f](https://github.com/zephyrproject-rtos/zephyr/commit/95c355c425763fbe5e735b9ef54dacce2c4ce21f)
- [https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fwmc-q8qg-jcxq](https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fwmc-q8qg-jcxq)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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