Auth bypass in N8n
CVE-2026-77073
n8n versions before 2.34.1 contain a credential validation bypass in the MCP create_workflow_from_code tool when authentication type is set to an expression. Attackers with a valid MCP Bearer API key and knowledge of a target credential ID can persist unauthorized cross-project credential references on workflows in different projects.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (25.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 25.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- N8n — versions 2.34.0
- N8n-Io N8n
Weakness classification (CWE)
References
- github.com/n8n-io/n8n/security/advisories/GHSA-vfrj-582q-mvcp (vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/n8n-before-cross-project-credential-access-via-mcp (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-77073?
- CVE-2026-77073 is a medium-severity vulnerability in N8n, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2026-08-20.
- How severe is CVE-2026-77073?
- Medium severity. CVSS v3 base score is 4.3 out of 10.