Your RAG Guardrail Can Rank Lies Above the Truth
A document with a 0.95 cosine match can be fabricated, while the grounded answer sits at 0.60 or rank four, outside the model’s context window. The practical attack is simple: seed text that resembles the questions your system expects, then give it enough authoritative framing to win retrieval. Similarity helps find relevant language; it cannot establish truth, provenance, or permission to trust the result.