Analysis
20 Prompt Injection Techniques Every Red Teamer Should Test | by Facundo Fernandez
First reported · Discovered medium.com
Page published
Earliest dated coverage: 4 Sep 2025 · First observed: 25 Oct 2026 · Latest dated coverage: 4 Sep 2025
Coverage timeline
Single-source analysis — one report is available.
Why it matters
Fernandez’s checklist offers defenders a starting point for broadening prompt-injection testing, although the available excerpt provides no evidence of effectiveness against specific systems.
Facundo Fernandez’s article presents a red-team checklist of 20 prompt-injection techniques across seven categories for assessing LLM applications, copilots, and agentic integrations. The available excerpt introduces direct instruction overrides with a high-level payload example, rather than demonstrating a new exploit or reporting a compromise.