CVE-2026-0863
Using string formatting and exception handling, an attacker may bypass n8n's python-task-executor sandbox restrictions and run arbitrary unrestricted Python code in the underlying operating system.
The vulnerability can be exploited via the Code block by an authenticated user with basic permissions and can lead to a full n8n instance takeover on instances operating under "Internal" execution mode.
If the instance is operating under the "External" execution mode (ex. n8n's official Docker image) - arbitrary code execution occurs inside a Sidecar container and not the main node, which significantly reduces the vulnerability impact.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Puntuación base: 9.9
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 9.42%
- Percentil entre todas las CVEs puntuadas: 95
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1210Exploitation of Remote Serviceslateral movement85 % - Impacto principal
T1059Command and Scripting Interpreterexecution90 % - Impacto secundario
T1068Exploitation for Privilege Escalationprivilege escalation75 %
Acceso autenticado en red (PR:L sin UI) a servicio remoto n8n. Ejecución arbitraria de Python en el SO. Escalada potencial a takeover completo en modo 'Internal'.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-95
- CWE-94
Referencias
- https://github.com/n8n-io/n8n/commit/b73a4283cb14e0f27ce19692326f362c7bf3da02
- https://research.jfrog.com/vulnerabilities/n8n-python-runner-sandbox-escape-jfsa-2026-001651077/
- https://www.smartkeyss.com/post/cve-2026-0863-python-sandbox-escape-in-n8n-via-exception-formatting-and-implicit-code-execution
- https://research.jfrog.com/vulnerabilities/n8n-python-runner-sandbox-escape-jfsa-2026-001651077/
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-0863",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-0863",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-01-20T16:42:52.853699Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "reefs@jfrog.com",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 8.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 6,
"exploitabilityScore": 1.8
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 9.9,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 6,
"exploitabilityScore": 3.1
}
]
},
"affected": [
{
"source": "reefs@jfrog.com",
"affectedData": [
{
"versions": [
{
"status": "affected",
"version": "2.4.0",
"lessThan": "2.4.2",
"versionType": "semver"
},
{
"status": "affected",
"version": "0",
"lessThan": "1.123.14",
"versionType": "semver"
},
{
"status": "affected",
"version": "2.0.0",
"lessThan": "2.3.5",
"versionType": "semver"
}
],
"packageName": "n8n",
"collectionURL": "https://www.npmjs.com"
}
]
}
],
"published": "2026-01-18T16:15:50.450",
"references": [
{
"url": "https://github.com/n8n-io/n8n/commit/b73a4283cb14e0f27ce19692326f362c7bf3da02",
"tags": [
"Patch"
],
"source": "reefs@jfrog.com"
},
{
"url": "https://research.jfrog.com/vulnerabilities/n8n-python-runner-sandbox-escape-jfsa-2026-001651077/",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "reefs@jfrog.com"
},
{
"url": "https://www.smartkeyss.com/post/cve-2026-0863-python-sandbox-escape-in-n8n-via-exception-formatting-and-implicit-code-execution",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://research.jfrog.com/vulnerabilities/n8n-python-runner-sandbox-escape-jfsa-2026-001651077/",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "reefs@jfrog.com",
"description": [
{
"lang": "en",
"value": "CWE-95"
}
]
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-94"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Using string formatting and exception handling, an attacker may bypass n8n's python-task-executor sandbox restrictions and run arbitrary unrestricted Python code in the underlying operating system.\n\nThe vulnerability can be exploited via the Code block by an authenticated user with basic permissions and can lead to a full n8n instance takeover on instances operating under \"Internal\" execution mode.\n\nIf the instance is operating under the \"External\" execution mode (ex. n8n's official Docker image) - arbitrary code execution occurs inside a Sidecar container and not the main node, which significantly reduces the vulnerability impact."
},
{
"lang": "es",
"value": "Usando formato de cadenas y manejo de excepciones, un atacante puede eludir las restricciones del sandbox python-task-executor de n8n y ejecutar código Python arbitrario sin restricciones en el sistema operativo subyacente.\n\nLa vulnerabilidad puede ser explotada a través del bloque de Código por un usuario autenticado con permisos básicos y puede llevar a una toma de control completa de la instancia de n8n en instancias que operan bajo el modo de ejecución 'Internal'.\n\nSi la instancia está operando bajo el modo de ejecución 'External' (ej. la imagen oficial de Docker de n8n) - la ejecución de código arbitrario ocurre dentro de un contenedor Sidecar y no en el nodo principal, lo que reduce significativamente el impacto de la vulnerabilidad."
}
],
"lastModified": "2026-06-17T10:11:31.430",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*",
"vulnerable": true,
"matchCriteriaId": "C80B3A94-5FBD-4713-BA71-7E1FD4999072",
"versionEndIncluding": "1.123.14"
},
{
"criteria": "cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*",
"vulnerable": true,
"matchCriteriaId": "50811F6D-ED48-4B09-BC5F-09D60EE44ABD",
"versionEndIncluding": "2.3.5",
"versionStartIncluding": "2.0.0"
},
{
"criteria": "cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*",
"vulnerable": true,
"matchCriteriaId": "ADF10FAB-9911-4234-A45B-0A067A5B0DD7",
"versionEndIncluding": "2.4.2",
"versionStartIncluding": "2.4.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "reefs@jfrog.com"
}