Geminijack: a Prompt-Injection Challenge Demonstrating Real-World LLM Abuse

A few days ago, a research team disclosed GeminiJack, a prompt-injection vulnerability affecting LLM-powered applications.

I recreated the same class of vulnerability as an interactive challenge to demonstrate how subtle prompt injection flaws can bypass guardrails, alter model behavior, and lead to unintended actions in real systems.

This is not a write-up, but a hands-on challenge. If you’re working with LLM apps, RAG pipelines, or AI agents, you can try breaking it yourself and see where traditional controls fail.

Happy to discuss the technical details, threat model, and mitigations in the comments.