Improper access control in n8n - #VU140993
Published: August 5, 2026
Vulnerability details
The vulnerability allows a remote user to bind a credential from another project to a workflow.
The vulnerability exists due to improper access control in the MCP create_workflow_from_code tool when validating credential references for nodes whose authentication type is set by an expression. A remote user can submit crafted workflow code referencing a credential ID from another project to bind a credential from another project to a workflow.
Exploitation requires MCP to be enabled, a valid MCP Bearer API key, and knowledge of a target credential ID from another project. The runtime execution path still blocks use of the foreign credential, so no credential secret is exposed and no actual requests are made with it.