This research reveals how attackers can exploit structured output formats to bypass LLM safety mechanisms, exposing a critical security vulnerability in AI systems.

• Identifies Constrained Decoding Attack method that uses grammar-guided outputs to evade safety filters
• Demonstrates how structured output APIs (JSON, XML, etc.) create blind spots in safety mechanisms
• Shows attackers can generate harmful content by exploiting output constraints that are typically used for functionality
• Highlights urgent need for security measures specifically designed for structured output scenarios

This research is crucial for security teams as it exposes how features designed to improve LLM usability can inadvertently create exploitable vulnerabilities, requiring immediate defensive strategies for AI systems with structured output capabilities.

Output Constraints as Attack Surface: Exploiting Structured Generation to Bypass LLM Safety Mechanisms