What is CVE-2026-54052?

CVE-2026-54052 is a critical-severity vulnerability in Czlonkowski N8n-Mcp, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 9.9/10. Published 2026-07-15.

How severe is CVE-2026-54052?

Critical severity. CVSS v3 base score is 9.9 out of 10.

Auth bypass in Czlonkowski N8n-Mcp

CVE-2026-54052

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.56.1, in HTTP mode with multi-tenancy enabled through ENABLE_MULTI_TENANT=true, n8n-mcp's local workflow version history backups were not isolated per tenant, allowing an authenticated tenant to read workflow version snapshots belonging to other tenants and delete or destroy other tenants' stored backups, including full node definitions, credential references, and authorization headers. This issue is fixed in version 2.56.1.

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.004 (31.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L.

Affected products

Czlonkowski N8n-mcp — versions < 2.56.1
N8n-mcp

Weakness classification (CWE)

References

security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
security-advisories@github.com (x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2026-54052?: CVE-2026-54052 is a critical-severity vulnerability in Czlonkowski N8n-Mcp, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 9.9/10. Published 2026-07-15.
How severe is CVE-2026-54052?: Critical severity. CVSS v3 base score is 9.9 out of 10.