Path Traversal in Koenkk Zigbee2mqtt

CVE-2026-71279

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.

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.004 (30.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-71279?
CVE-2026-71279 is a high-severity vulnerability in Koenkk Zigbee2mqtt, classified under Path Traversal. CVSS score: 8.0/10. Published 2026-08-05.
How severe is CVE-2026-71279?
High severity. CVSS v3 base score is 8.0 out of 10.