← Back to CVE Explorer

CVE-2026-58057

Full vulnerability record from the local CVENow database.

Description

Flowise before 3.1.3 validates Custom MCP stdio environment variables against a denylist using a case-sensitive comparison, so on Windows, where environment names are case-insensitive, supplying 'node_options' bypasses the NODE_OPTIONS denylist entry. An authenticated user who can configure a Custom MCP node can thereby inject NODE_OPTIONS --require and execute arbitrary code in the Flowise server context.

Severity
LOW
CVSS score
2.3 (v4.0)
Vulnerability status
Analyzed
Source identifier
Published
2026-06-28 02:16:32.990000
Last modified
2026-10-25 17:10:00.197000
View original CVE JSON
{
  "id": "CVE-2026-58057",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-28T02:16:32.990",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Flowise before 3.1.3 validates Custom MCP stdio environment variables against a denylist using a case-sensitive comparison, so on Windows, where environment names are case-insensitive, supplying 'node_options' bypasses the NODE_OPTIONS denylist entry. An authenticated user who can configure a Custom MCP node can thereby inject NODE_OPTIONS --require and execute arbitrary code in the Flowise server context."
    },
    {
      "lang": "es",
      "value": "Flowise antes de la versión 3.1.3 valida las variables de entorno stdio de Custom MCP contra una lista de denegación utilizando una comparación que distingue entre mayúsculas y minúsculas, por lo que en Windows, donde los nombres de las variables de entorno no distinguen entre mayúsculas y minúsculas, proporcionar ’node_options’ elude la entrada NODE_OPTIONS de la lista de denegación. Un usuario autenticado que puede configurar un nodo Custom MCP puede así inyectar NODE_OPTIONS --require y ejecutar código arbitrario en el contexto del servidor Flowise."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Flowise",
          "product": "Flowise",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/flowise",
          "versions": [
            {
              "version": "0",
              "lessThan": "3.1.3",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "3.1.3",
              "versionType": "semver",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 2.3,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "LOW",
          "vulnAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L",
          "baseScore": 5.0,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 3.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-06-29T12:23:43.023783Z",
          "id": "CVE-2026-58057",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-178"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "3.1.3",
              "matchCriteriaId": "8C8B3FC2-6070-4400-9690-FCBE0C5C1D37"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/FlowiseAI/Flowise/pull/6471",
      "source": "[email protected]",
      "tags": [
        "Issue Tracking",
        "Patch"
      ]
    },
    {
      "url": "https://github.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-poc",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.vulncheck.com/advisories/flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Patch",
        "Third Party Advisory"
      ]
    }
  ]
}