Auth bypass in N8n
CVE-2026-56776
n8n before 1.123.55, 2.25.7, and 2.26.2 contains an authorization bypass in the POST /workflows/{workflowId}/test-runs/new endpoint, which authorizes access using the workflow:read scope instead of workflow:execute. An authenticated user with read-only access to a workflow can trigger a real evaluation test run, causing the workflow to execute via the internal workflow runner and resulting in unintended outbound API calls, data mutations, or other side effects in connected downstream systems. The issue primarily affects instances using the Evaluations feature where RBAC project roles grant workflow:read without workflow:execute.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (18.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 18.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- N8n — versions 0, 1.123.55, 2.26.2
Weakness classification (CWE)
References
- github.com/n8n-io/n8n/security/advisories/GHSA-hv7x-3x78-gx53 (vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/n8n-incorrect-oauth-scope-validation-in-workflow-t… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-56776?
- CVE-2026-56776 is a high-severity vulnerability in N8n, classified under Incorrect Authorization. CVSS score: 7.4/10. Published 2026-07-08.
- How severe is CVE-2026-56776?
- High severity. CVSS v3 base score is 7.4 out of 10.