CVE-2026-71279

Zigbee2MQTT External JS Extension Path Traversal Leading to Remote Code Execution

State: Published
Severity: 8.1 High
Published: Aug 5, 2026
Updated: Aug 10, 2026
Reserved: Aug 5, 2026

Description

Zigbee2MQTT's ExternalJSExtension.getFilePath (lib/extension/externalJS.ts) joins a parameter received via an MQTT message (topic zigbee2mqtt/bridge/request/extension/save) into the extensions base path using path.join(basePath, name) with no sanitization. The extension handler only validates that the name ends in .js/.mjs/.cjs, writes the file, and then dynamically imports it via Node.js import, achieving remote code execution.

Scores

CVSS	Score	Vector	Source
3.1	8.1 High	CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	TuranSec

Weaknesses

CWE-22

Affected Products

Product	Versions
zigbee2mqttKoenkk	2.12.0 and earlierAffected

References

https://github.com/Koenkk/zigbee2mqttthird-party-advisory
https://github.com/Koenkk/zigbee2mqtt/blob/master/lib/extension/externalJS.tsthird-party-advisory

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