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

Summary

## 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.