n8n before 2.41.4 and 2.42.0 Authorization Bypass in Agent Chat Resume Tool Approval

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.