Auth bypass in N8n
CVE-2026-85166
n8n before 2.35.4 and 2.36.x before 2.36.2 does not validate credential references in the inline workflow JSON of nodes that execute an inline sub-workflow (e.g., the Workflow Tool node). A shared-workflow editor, or any user creating/updating a workflow via the REST API, Public API, or MCP, can persist a node referencing a credential they do not own. When the workflow is later executed under an identity that holds the credential, the inline sub-workflow resolves the secret and can send it to an attacker-controlled endpoint, resulting in credential exfiltration.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (28.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.0% 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: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/n8n-io/n8n/security/advisories/GHSA-4r56-g65c-fm83 (vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/n8n-before-2.36.2-credential-exfiltration-via-work… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-85166?
- CVE-2026-85166 is a medium-severity vulnerability in N8n, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-09-03.
- How severe is CVE-2026-85166?
- Medium severity. CVSS v3 base score is 6.5 out of 10.