CVE-2026-56776 n8n - Incorrect OAuth Scope Validation in Workflow Test Run Endpoint

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...