n8n before 2.41.4 and 2.42.0 contains an authorization bypass in the agent chat resume endpoint, which accepts a run identifier from the request body without verifying that the suspended checkpoint belongs to the caller. Authenticated project members can list and read other members' private agent conversations through project-scoped endpoints, then approve their pending tool calls, causing the tools to execute and write results into the victim's conversation.

n8n before 2.41.4 and 2.42.0 contains an authorization bypass in the agent chat resume endpoint, which accepts a run identifier from the request body without verifying that the suspended checkpoint belongs to the caller. Authenticated project members can list and read other members' private agent conversations through project-scoped endpoints, then approve their pending tool calls, causing the tools to execute and write results into the victim's conversation.