Breaking Instruction Hierarchy in OpenAI's gpt-4o-mini. Johann Rehberger digs further into GPT-4o's "instruction hierarchy" protection and finds that it has little impact at all on common prompt injection approaches.
I spent some time this weekend to get a better intuition about
gpt-4o-mini
model and instruction hierarchy, and the conclusion is that system instructions are still not a security boundary.From a security engineering perspective nothing has changed: Do not depend on system instructions alone to secure a system, protect data or control automatic invocation of sensitive tools.
Recent articles
- I think "agent" may finally have a widely enough agreed upon definition to be useful jargon now - 18th September 2025
- My review of Claude's new Code Interpreter, released under a very confusing name - 9th September 2025
- Recreating the Apollo AI adoption rate chart with GPT-5, Python and Pyodide - 9th September 2025