Flowise – Custom MCP Environment Variable Denylist Bypass via Case Sensitivity_CVE-2026-58057

{
    "lastseen": "",
    "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.",
    "published": "2026-06-28T01:32:58.594Z",
    "modified": "2026-06-28T01:32:58.594Z",
    "type": "cve",
    "title": "Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity",
    "source": "VulnCheck",
    "references": "https://github.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-poc\nhttps://github.com/FlowiseAI/Flowise/pull/6471\nhttps://www.vulncheck.com/advisories/flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity",
    "id": "CVE-2026-58057",
    "bulletinFamily": "",
    "cwe": [
        "CWE-178"
    ],
    "cvelist": null,
    "sourceData": "Flowise Flowise 0",
    "sourceHref": "",
    "cvss": {
        "score": 5,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Flowise",
    "version": "0",
    "vendor": "Flowise",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}