n8n: Shared-Workflow Editor Can Exfiltrate Credentials via Inline Sub-Workflow JSON

Impact

n8n's credential-access checks validated only a node's top-level credentials, not credentials referenced inside an Execute Sub-workflow node's inline workflow JSON. A member with editor access to a shared workflow could reference a credential they were not permitted to use inside that inline JSON; it passed both save-time and runtime validation and resolved in the parent workflow's project context, letting the member use or exfiltrate a credential they could not otherwise access.

Exploitation requires workflow sharing to be enabled and the attacker to have been explicitly granted Editor access to a shared workflow. The attacker must also know the target credential's ID.

Patches

The issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

• Restrict workflow sharing to fully trusted users only, and avoid granting Editor access to untrusted members on workflows that use sensitive credentials.
• Audit shared workflows for Execute Sub-workflow nodes with Source = "Parameter" and review their inline workflow definitions for unexpected credential references.
• Restrict network egress from the n8n instance to prevent connections to attacker-controlled endpoints.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.