CVE-2026-42228: n8n Vulnerable to Hijacking of Unauthenticated Chat Execution

The /chat WebSocket endpoint used by the Chat Trigger node’s Hosted Chat feature did not verify that an incoming connection was authorized to interact with the target execution. An unauthenticated remote attacker who could identify a valid execution ID for a workflow in a waiting state could attach to that execution, receive the pending prompt intended for the legitimate user, and submit arbitrary input to resume or influence downstream workflow behavior.

Exploitation requires the following conditions:

• The instance exposes a public Hosted Chat workflow with authentication set to None.
• A target execution is in a waiting state at the time of the attack.
• The attacker can obtain or discover the execution ID of that waiting execution.