CVE-2026-73601
Full vulnerability record from the local CVENow database.
Description
Flowise versions before 3.1.3 contain a remote code execution vulnerability in the Custom MCP node when CUSTOM_MCP_PROTOCOL is set to stdio, allowing authenticated users to execute arbitrary commands by manipulating environment variables and command arguments. Attackers can abuse PYTHONWARNINGS and BROWSER environment variables with python3, or leverage the root working directory with node to bypass validation and execute system commands.
Severity
CRITICAL
CVSS score
9.0
(v4.0)
Vulnerability status
Analyzed
Source identifier
Published
2026-08-13 12:17:24.353000
Last modified
2026-10-24 15:10:00.190000
View original CVE JSON
{
"id": "CVE-2026-73601",
"sourceIdentifier": "[email protected]",
"published": "2026-08-13T12:17:24.353",
"lastModified": "2026-10-24T15:10:00.190",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Flowise versions before 3.1.3 contain a remote code execution vulnerability in the Custom MCP node when CUSTOM_MCP_PROTOCOL is set to stdio, allowing authenticated users to execute arbitrary commands by manipulating environment variables and command arguments. Attackers can abuse PYTHONWARNINGS and BROWSER environment variables with python3, or leverage the root working directory with node to bypass validation and execute system commands."
},
{
"lang": "es",
"value": "Las versiones de Flowise anteriores a la 3.1.3 contienen una vulnerabilidad de ejecución remota de código en el nodo Custom MCP cuando CUSTOM_MCP_PROTOCOL está configurado como stdio, lo que permite a usuarios autenticados ejecutar comandos arbitrarios manipulando variables de entorno y argumentos de comando. Los atacantes pueden abusar de las variables de entorno PYTHONWARNINGS y BROWSER con python3, o aprovechar el directorio de trabajo raíz con node para eludir la validación y ejecutar comandos del sistema."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "FlowiseAI",
"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"
}
]
},
{
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"product": "Flowise",
"defaultStatus": "unaffected",
"packageURL": "pkg:npm/flowise-components",
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"status": "affected"
},
{
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"versionType": "semver",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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": 9.0,
"baseSeverity": "CRITICAL",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"vulnAvailabilityImpact": "HIGH",
"subConfidentialityImpact": "HIGH",
"subIntegrityImpact": "HIGH",
"subAvailabilityImpact": "HIGH",
"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": "Primary",
"cvssData": {
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"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 8.8,
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"attackVector": "NETWORK",
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"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
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"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.8,
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}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-08-14T18:59:26.374654Z",
"id": "CVE-2026-73601",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-95"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
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],
"references": [
{
"url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-g98q-rm45-q9h8",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
},
{
"url": "https://www.vulncheck.com/advisories/flowise-before-remote-code-execution-via-custom-mcp",
"source": "[email protected]",
"tags": [
"Third Party Advisory"
]
}
]
}