Medium · published September 3, 2026
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.
| Product | Versions | Fixed in |
|---|---|---|
| n8n/n8n | < 2.35.4 | 2.35.4 |
| n8n/n8n | ≥ 2.36.0, < 2.36.2 | 2.36.2 |