LLM-as-a-judge systems and automated LLM evaluators are vulnerable to meaning-preserving perturbations, specifically formatting alterations and verbosity manipulations. When grading or classifying text and agentic transcripts, LLM judges exhibit high sensitivity to layout-only changes (such as whitespace and indentation) and response length, frequently altering their scores even when the underlying semantic and factual content remains identical. This allows attackers to bypass automated safety…
Source: arXiv