Comment and Control: How Prompt Injection in Code Comments Can Steal API Keys from Claude Code, Gemini CLI, and GitHub Copilot

Originally published on CoreProse KB-incidents Code comments used to be harmless notes. With LLM tooling, they’re an execution surface. When Claude Code, Gemini CLI, or GitHub Copilot Agents read your repo, they usually see: system prompt + developer instructions + file contents (including comments)