CVE-2026-56776
MEDIUM 5.3n8n 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.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 6th percentile
Impact if exploited
5.3CVSS 4.0 · MEDIUM
- ConfidentialityLow
- IntegrityLow
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-56776/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-56776/poc.json
Weakness (CWE)
- CWE-863: Incorrect Authorization
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| N8n | N8n | < 1.123.55 |
| N8n | N8n | ≥ 2.0.0 and < 2.25.7 |
| N8n | N8n | ≥ 2.26.0 and < 2.26.2 |
All CVSS metrics
- MEDIUM 5.3 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L - HIGH 7.4 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L - MEDIUM 5.3 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - HIGH 7.4 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L