n8n before 1.123.67, 2.31.5, and 2.32.1 validates credential-access only for a node's top-level credentials and not for credentials referenced inside an Execute Sub-workflow node's inline workflow JSON. A member with Editor access to a shared workflow (when workflow sharing is enabled) who knows a target credential's ID can reference that credential in the inline JSON; it passes save-time and runtime validation and resolves in the parent workflow's project context, allowing the attacker to use or exfiltrate credentials they are not permitted to access.
Analyzing vulnerability vectors…