CVE-2026-56776

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 61/100
Published: 2026-07-08 Modified: 2026-10-29 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
AT: None
VC: Low
VI: Low
VA: Low

Description

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.

Weakness Classification (1)

Affected Software (5)

VendorProductVersion
n8n n8n 0 < 1.123.55
n8n n8n < 1.123.55
n8n n8n 0 < 1.123.55
n8n n8n 2.26.0 < 2.26.2
n8n n8n 2.0.0-rc.0 < 2.25.7

Bug Bounty Relevance

61 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

5.3 / 10.0 v4.0
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

EPSS — Exploitation Probability

0.28%
Raw Score 0.002760
Percentile 20.0%
Date 2026-10-29

Intelligence Sources

mitre ref →
nvd ref →