Analysis · curated 26 Jul 2026
One Poisoned Agent Infects the Whole Chain | Ravoid
First reported · updated · 2 reports arthur.ai
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Why it matters
Multi-agent architectures expand the blast radius of prompt injection because a compromised agent's output is executed with the next agent's permissions, turning a bad answer into a bad action such as data exfiltration or unauthorized tool calls.
An explainer on how prompt injection propagates across multi-agent LLM systems, showing that a payload buried in a retrieved document, tool result, subagent output, or shared memory becomes trusted input to downstream agents and rides the chain past a single front-door guardrail. The piece argues every inter-agent handoff must be treated as a trust boundary and references the 'Prompt Infection' research on self-replicating LLM-to-LLM injection.