n8n-MCP: Multi-tenant MCP requests fall back to process-level n8n credentials when tenant headers are absent or incomplete_CVE-2026-45707

{
    "lastseen": "",
    "description": "n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.51.2, when ENABLE_MULTI_TENANT=true, the HTTP transport documents that the target n8n instance is selected per-request from x-n8n-url / x-n8n-key headers. Requests that omitted those headers \u2014 or supplied only one of them \u2014 silently fell back to the process-level N8N_API_URL / N8N_API_KEY credentials configured for the operator's own n8n instance. As a result, an authenticated MCP tenant could cause n8n management calls to execute against the operator's instance instead of its own. This affects HTTP-mode deployments of n8n-mcp that are run as a shared multi-tenant service. Single-tenant deployments (ENABLE_MULTI_TENANT unset or false) are not affected. This vulnerability is fixed in 2.51.2.",
    "published": "2026-05-29T13:35:42.281Z",
    "modified": "2026-05-29T13:35:42.281Z",
    "type": "cve",
    "title": "n8n-MCP: Multi-tenant MCP requests fall back to process-level n8n credentials when tenant headers are absent or incomplete",
    "source": "GitHub_M",
    "references": "https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-jxx9-px88-pj69\nhttps://github.com/czlonkowski/n8n-mcp/commit/853015d0897be7cf2d9d4726de195c938e4395ab\nhttps://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.2",
    "id": "CVE-2026-45707",
    "bulletinFamily": "",
    "cwe": [
        "CWE-284"
    ],
    "cvelist": null,
    "sourceData": "czlonkowski n8n-mcp < 2.51.2",
    "sourceHref": "",
    "cvss": {
        "score": 8.1,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
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        "baseScore": 0,
        "baseSeverity": "",
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        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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            "baseScore": 0,
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "n8n-mcp",
    "version": "< 2.51.2",
    "vendor": "czlonkowski",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
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    "ai_score": 0
}