| Component | n8n |
| Severity | high (CVSS 8.1) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| Published (NVD) | 2026-05-29 |
| Last modified | 2026-07-21 |
| Affected versions | n8n-mcp < 2.51.2 |
| Fixed in | 2.51.2 |
| Weakness | CWE-284 |
| CISA KEV | not listed |
NVD 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 — or supplied only one of them — 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.
What to do
- Upgrade n8n to
2.51.2or later. - Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
- NVD: CVE-2026-45707
- https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-jxx9-px88-pj69
- https://github.com/czlonkowski/n8n-mcp/commit/853015d0897be7cf2d9d4726de195c938e4395ab
- https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.2
Read more
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