CVE-2026-12940
IBM Langflow OSS 1.0.0 through 1.10.1 are vulnerable to unauthenticated remote code execution via environment variable injection in the MCP (Model Context Protocol) stdio launcher. The vulnerability exists in src/lfx/src/lfx/base/mcp/util.py where the DANGEROUS_ENV_VARS blocklist fails to include SHELLOPTS , BASHOPTS , and PS4 environment variables.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.94%
- Percentil entre todas las CVEs puntuadas: 60
- 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
T1190Exploit Public-Facing Applicationinitial access95 % - Impacto principal
T1059Command and Scripting Interpreterexecution90 %
Vector CVSS AV:N/AC:L/PR:N/UI:N indica exposición remota sin autenticación ni interacción. CWE-78 (OS Command Injection) y descripción de inyección de variables de entorno para ejecución de código remota en MCP launcher justifican T1190 como explotación y T1059 como impacto.
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-78
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-12940",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-12940",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-07-30T00:00:00+00:00"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "psirt@us.ibm.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.8,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "psirt@us.ibm.com",
"affectedData": [
{
"cpes": [
"cpe:2.3:a:ibm:langflow_oss:1.0.0:*:*:*:*:*:*:*",
"cpe:2.3:a:ibm:langflow_oss:1.10.1:*:*:*:*:*:*:*"
],
"vendor": "IBM",
"product": "Langflow OSS",
"versions": [
{
"status": "affected",
"version": "1.0.0",
"versionType": "semver",
"lessThanOrEqual": "1.10.1"
}
]
}
]
}
],
"published": "2026-07-30T17:16:28.040",
"references": [
{
"url": "https://www.ibm.com/support/pages/node/7279995",
"tags": [
"Vendor Advisory"
],
"source": "psirt@us.ibm.com"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "psirt@us.ibm.com",
"description": [
{
"lang": "en",
"value": "CWE-78"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "IBM Langflow OSS 1.0.0 through 1.10.1 are vulnerable to unauthenticated remote code execution via environment variable injection in the MCP (Model Context Protocol) stdio launcher. The vulnerability exists in src/lfx/src/lfx/base/mcp/util.py where the DANGEROUS_ENV_VARS blocklist fails to include SHELLOPTS , BASHOPTS , and PS4 environment variables."
}
],
"lastModified": "2026-08-04T20:20:28.103",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "362B13B6-4992-423F-98D3-60056848503C",
"versionEndExcluding": "1.10.2",
"versionStartIncluding": "1.0.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "psirt@us.ibm.com"
}