Flowise – Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess_CVE-2026-56274

{
    "lastseen": "",
    "description": "Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature due to incomplete command-flag validation and a regex bypass in local file access restrictions. An attacker with a Flowise account of any role, or API access with view/update permissions for chatflows, can configure a malicious MCP server to bypass the validateCommandFlags blocklist (for example, 'docker build' is not blocked, and 'npx --yes' is not blocked while only '-y' is) and the validateArgsForLocalFileAccess checks, resulting in execution of arbitrary commands on the Flowise host.",
    "published": "2026-06-23T12:13:00.703Z",
    "modified": "2026-06-23T12:13:00.703Z",
    "type": "cve",
    "title": "Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess",
    "source": "VulnCheck",
    "references": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q\nhttps://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess",
    "id": "CVE-2026-56274",
    "bulletinFamily": "",
    "cwe": [
        "CWE-78"
    ],
    "cvelist": null,
    "sourceData": "Flowise Flowise 0\nFlowise Flowise 0",
    "sourceHref": "",
    "cvss": {
        "score": 8.7,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "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": "Remote code execution vulnerability via MCP security bypass in validateCommandFlags and validateArgsForLocalFileAccess",
    "ai_severity": "High",
    "ai_vendor": "Flowise",
    "ai_product": "Flowise",
    "ai_version": "before 3.1.2",
    "ai_score": 8.7
}