---
title: "CVE-2026-19741: Zephyr OpenThread - Authentication Bypass"
description: "Zephyr OpenThread integration contains an authentication bypass caused by a default publicly known Joining Device Credential (PSKd) in CONFIG_OPENTHREAD_JOINER_PSKD, letting unauthenticated attackers within radio range join and control uncommissioned devices, exploit requires joiner autostart enabled with default PSKd."
url: https://panop.io/threat-heartbeat/CVE-2026-19741/
---

# CVE-2026-19741 Zephyr OpenThread - Authentication Bypass

Zephyr OpenThread integration contains an authentication bypass caused by a default publicly known Joining Device Credential (PSKd) in CONFIG\_OPENTHREAD\_JOINER\_PSKD, letting unauthenticated attackers within radio range join and control uncommissioned devices, exploit requires joiner autostart enabled with default PSKd.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.27% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-19741)

## Details

Type

Authentication Bypass

Impact

Broken Authentication

CVSS vector

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

Published

23 October 2026

Updated

25 October 2026

Weakness

[CWE-1392](https://cwe.mitre.org/data/definitions/1392.html)

## Vendor fix

Remove default PSKd and provision unique per-device PSKd; disable joiner autostart or set a secure PSKd.

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-2026-19741](https://nvd.nist.gov/vuln/detail/CVE-2026-19741)
- [https://github.com/zephyrproject-rtos/zephyr/commit/acb3e514d7fab2bc9672acaba8019d2dc91b187c](https://github.com/zephyrproject-rtos/zephyr/commit/acb3e514d7fab2bc9672acaba8019d2dc91b187c)
- [https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-6j2r-xrm4-3v7f](https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-6j2r-xrm4-3v7f)

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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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