Why Claude Haiku Returned UNCERTAIN: Anatomy of an Indirect Prompt Injection in an Agentic System

This post explains an important AI security lesson:

Sometimes the most important result is not PASS or FAIL — it’s UNCERTAIN.

In this evaluation, Claude Haiku resisted more obvious prompt injection patterns, but a subtle context prefix still influenced tool behavior inside an agentic workflow.

Why that matters:

• the task still looked mostly normal

• there was no obvious jailbreak

• but the model’s behavior shifted in a meaningful way

That is exactly why AI agent testing must go beyond chatbot-style prompt checks and focus on behavioral evaluation.

Read the full post here:
https://agentsafelabs.com/blog/why-claude-haiku-returned-uncertain-anatomy-of-an-indirect-prompt-injection-in-an-agentic-system/

#AISecurity #PromptInjection #LLMSecurity #AIAgents #CyberSecurity #AgenticAI #ClaudeHaiku