CVE-2026-71279
Zigbee2MQTT External JS Extension Path Traversal Leading to Remote Code Execution
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.
INFO
Published Date :
Aug. 5, 2026, 1:24 p.m.
Last Modified :
Oct. 23, 2026, 9:10 p.m.
Remotely Exploit :
No
Source :
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c |
Solution
- Update Zigbee2MQTT to the latest version.
- Ensure the `enable_external_js` option is disabled.
- Restrict access to the MQTT broker.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-71279.
| URL | Resource |
|---|---|
| https://github.com/Koenkk/zigbee2mqtt | |
| https://github.com/Koenkk/zigbee2mqtt/blob/master/lib/extension/externalJS.ts |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-71279 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-71279
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-71279 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-71279 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Oct. 23, 2026
Action Type Old Value New Value Added Translation Title: zigbee2mqtt de Koenkk, Description: ExternalJSExtension.getFilePath() de Zigbee2MQTT (lib/extensión/externalJS.ts) une un parámetro ’name’ recibido a través de un mensaje MQTT (tema zigbee2mqtt/bridge/request/extensión/save) en la ruta base de las extensiones usando path.join(basePath, name) sin sanitización. Debido a que path.join() resuelve secuencias ’.. / ’, un nombre como ’.. / .. / tmp/evil.js’ escapa del directorio de extensiones previsto. El gestor de extensiones solo valida que el nombre termine en .js/.mjs/.cjs, escribe el archivo y luego lo importa dinámicamente a través de Node.js import(), logrando ejecución remota de código. Requiere la opción de configuración ’enable_external_js’ (desactivada por defecto, pero comúnmente habilitada en instalaciones heredadas) y acceso al broker MQTT, que con frecuencia no está autenticado en implementaciones reales. El idéntico getFilePath() no sanitizado también es utilizado por el gestor de eliminación de extensiones, permitiendo la eliminación arbitraria de archivos. -
CVE Modified by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 10, 2026
Action Type Old Value New Value Changed Description Zigbee2MQTT's ExternalJSExtension.getFilePath() (lib/extension/externalJS.ts) joins a `name` 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. Because path.join() resolves `../` sequences, a name such as `../../tmp/evil.js` escapes the intended extensions directory. 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. Requires the `enable_external_js` config option (off by default, but commonly enabled in legacy installs) and MQTT broker access, which is frequently unauthenticated in real deployments. The identical unsanitized getFilePath() is also used by the extension-removal handler, enabling arbitrary file deletion. 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. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 05, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-71279', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-05T15:55:04.507481Z'} -
New CVE Received by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 05, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Koenkk', 'product': 'zigbee2mqtt', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.12.0'}], 'programFiles': ['lib/extension/externalJS.ts'], 'defaultStatus': 'unaffected'}] Added Description Zigbee2MQTT's ExternalJSExtension.getFilePath() (lib/extension/externalJS.ts) joins a `name` 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. Because path.join() resolves `../` sequences, a name such as `../../tmp/evil.js` escapes the intended extensions directory. 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. Requires the `enable_external_js` config option (off by default, but commonly enabled in legacy installs) and MQTT broker access, which is frequently unauthenticated in real deployments. The identical unsanitized getFilePath() is also used by the extension-removal handler, enabling arbitrary file deletion. Added CVSS V3.1 AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-22 Added Reference https://github.com/Koenkk/zigbee2mqtt Added Reference https://github.com/Koenkk/zigbee2mqtt/blob/master/lib/extension/externalJS.ts