A brief system-prompt warning gives near-total immunity to self-propagating ideas in multi-agent systems
arXiv 2608.10218·medium signal
Researchers evolved 'mind viruses' — self-propagating ideas that spread agent-to-agent through multi-agent LLM systems — and found harmful payloads propagate notably less effectively than benign ones. The actionable result is the defense: a brief warning in the system prompt conferred what the authors describe as near-total immunity. That is an unusually cheap mitigation for a failure mode that only appears once you have agents talking to each other, which is exactly the direction tooling shipped this week.