26 - 28 OCT 2026 Utrecht Netherlands

One arrow, multiple breaches: what I've learned jailbreaking AI chatbots

Room 8Wed 28 Oct • 09:45–10:45Architecture & SecurityIntroductory and overview
In medieval courts, a trusted advisor with the wrong loyalties could bring down a kingdom from the inside. LLM-powered apps have the same problem and most teams don't find out until it's too late. You've probably used an LLM API, everyone is building with LLMs right now - either to help them work or integrate into a product. Customer service bots, lifestyle assistants, internal tools with RAG pipelines sitting on top of company data. And most of them have security assumptions baked in that are... optimistic. This talk is about what actually happens when you start poking at these things. I'll walk through what I've found testing real LLM-powered apps: a knowledge base that turned out to give way more access than anyone intended, a lifestyle assistant that was so eager to help it forgot it had limits, and a few bypass techniques that made moderation feel more like a suggestion than a guardrail. One of them took a single prompt and I broke the Cyber Security Agency of Singapore's scammer bot in a way they didn't expect. This isn't a "here's how to be evil" talk — it's a "here's how these things actually fail so we can build them better" talk. We'll look at why LLM security is genuinely different from traditional app security, why prompt injection is a real problem and not just a fun party trick, and what practical steps you can actually take when you're integrating an LLM into a product. If you're building with AI, or you're working with a team that is, this one's for you. Key takeaways: - A tour of the most common ways LLM-integrated apps fail in the real world - Why knowledge bases and overly permissive agents running on your laptop introduce risks most devs don't anticipate - How moderation bypasses work and why they're harder to fix than they look - Practical things you can actually do to make your LLM integration more resilient and a bit of AI ethics sprinkled into the mix

About the speaker

Yianna Paris

Yianna Paris is a Senior Offensive Security Consultant and Trainer based in the Netherlands who lives at the intersection of software engineering and security — with a soft spot for hardware. She specialises in digital exposure, threat hunting and getting hands on by breaking systems: mapping real attack surfaces, finding what's leaking, and working with dev teams to fix it before someone else does. She particularly likes finding interesting logic bugs with secure code review and proving exploitability by hacking software. She doesn't work well with checkbox compliant - proving exploitability and risk is key. Helping organisations understand where they're vulnerable and how to secure their pipelines is what makes breaking that software the most fulfilling. She's spoken and run workshops at DEFCON, and has a particular obsession with wireless protocols, cloud and embedded systems, and the surprising number of things you can do with cheap hardware and a bit of patience. If it transmits a signal, she's probably tried to intercept it. Previously she lived in Australia where she also worked as a software engineer.