GHSA-2CF7-HPWF-47H9

Vulnerability from github – Published: 2026-07-14 20:26 – Updated: 2026-07-14 20:26
VLAI
Summary
n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode
Details

Summary

In multi-tenant HTTP mode (ENABLE_MULTI_TENANT=true), an authenticated tenant could, under certain conditions, reach n8n-mcp's local default-scope workflow_versions backups instead of being confined to its own tenant scope. This affects n8n-mcp's own local workflow-version storage, not a normal n8n API capability.

Impact

An authenticated MCP HTTP tenant could read or delete workflow-version backups stored in the default (single-tenant) scope — for example backups left from a prior single-tenant deployment or a migration period. Workflow snapshots may contain sensitive workflow configuration depending on their contents. Single-tenant and stdio deployments are not affected.

Affected versions

<= 2.57.3

Patched version

2.57.4

Remediation

Upgrade to n8n-mcp 2.57.4 or later. The fix requires a complete tenant context in multi-tenant mode and fails closed for workflow-version access that cannot be attributed to a specific tenant.

Workarounds

  • Restrict network access to the HTTP endpoint (firewall / reverse proxy / VPN) so only trusted callers can reach it.
  • Run in stdio mode, which has no multi-tenant HTTP surface.
  • If default-scope backups from a prior single-tenant deployment are not needed, removing them eliminates the exposure.

Credit

Reported by @DavidCarliez.

Severity
4.2 (Medium)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.57.3"
      },
      "package": {
        "ecosystem": "npm",
        "name": "n8n-mcp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.57.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55608"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200",
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-14T20:26:39Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nIn multi-tenant HTTP mode (`ENABLE_MULTI_TENANT=true`), an authenticated tenant could, under certain conditions, reach n8n-mcp\u0027s local default-scope `workflow_versions` backups instead of being confined to its own tenant scope. This affects n8n-mcp\u0027s own local workflow-version storage, not a normal n8n API capability.\n\n## Impact\n\nAn authenticated MCP HTTP tenant could read or delete workflow-version backups stored in the default (single-tenant) scope \u2014 for example backups left from a prior single-tenant deployment or a migration period. Workflow snapshots may contain sensitive workflow configuration depending on their contents. Single-tenant and stdio deployments are not affected.\n\n## Affected versions\n\n`\u003c= 2.57.3`\n\n## Patched version\n\n`2.57.4`\n\n## Remediation\n\nUpgrade to n8n-mcp `2.57.4` or later. The fix requires a complete tenant context in multi-tenant mode and fails closed for workflow-version access that cannot be attributed to a specific tenant.\n\n## Workarounds\n\n- Restrict network access to the HTTP endpoint (firewall / reverse proxy / VPN) so only trusted callers can reach it.\n- Run in stdio mode, which has no multi-tenant HTTP surface.\n- If default-scope backups from a prior single-tenant deployment are not needed, removing them eliminates the exposure.\n\n## Credit\n\nReported by @DavidCarliez.",
  "id": "GHSA-2cf7-hpwf-47h9",
  "modified": "2026-07-14T20:26:39Z",
  "published": "2026-07-14T20:26:39Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-2cf7-hpwf-47h9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/czlonkowski/n8n-mcp/commit/c1ca1e73697feaec5ec2a5fb7e6992a2892b62c9"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/czlonkowski/n8n-mcp"
    },
    {
      "type": "WEB",
      "url": "https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.57.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode"
}



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