VulnerabilityDeferred

CVE-2026-71279

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.

HIGH 8.0EPSS 0.36%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 8.0 HIGHCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.36% probability · 30th percentile
CISA KEV: Not listed
Weakness: CWE-22
Source: 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.