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CVE-2026-12940

Full vulnerability record from the local CVENow database.

Description

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.

Severity
CRITICAL
CVSS score
9.8 (v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-07-30 17:16:28.040000
Last modified
2026-10-23 22:10:00.160000
View original CVE JSON
{
  "id": "CVE-2026-12940",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-30T17:16:28.040",
  "lastModified": "2026-10-23T22:10:00.160",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "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."
    },
    {
      "lang": "es",
      "value": "IBM Langflow OSS 1.0.0 hasta 1.10.1 son vulnerables a la ejecución remota de código no autenticada mediante inyección de variables de entorno en el lanzador stdio de MCP (Protocolo de Contexto de Modelo). La vulnerabilidad reside en src/lfx/src/lfx/base/mcp/util.py, donde la lista de bloqueo DANGEROUS_ENV_VARS no incluye las variables de entorno SHELLOPTS, BASHOPTS y PS4."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "IBM",
          "product": "Langflow OSS",
          "cpes": [
            "cpe:2.3:a:ibm:langflow_oss:1.0.0:*:*:*:*:*:*:*",
            "cpe:2.3:a:ibm:langflow_oss:1.10.1:*:*:*:*:*:*:*"
          ],
          "versions": [
            {
              "version": "1.0.0",
              "lessThanOrEqual": "1.10.1",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-30T00:00:00+00:00",
          "id": "CVE-2026-12940",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-78"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "1.0.0",
              "versionEndExcluding": "1.10.2",
              "matchCriteriaId": "362B13B6-4992-423F-98D3-60056848503C"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://www.ibm.com/support/pages/node/7279995",
      "source": "[email protected]",
      "tags": [
        "Vendor Advisory"
      ]
    }
  ]
}