Encrypted instructions trick Copilot CLI into spilling developer secrets

GitHub Copilot CLI can be made to read sensitive files from a developer’s machine and send their contents to an attacker from a single web page. Security researchers at Adversa AI said the new attack technique, dubbed Cryptographic Context Injection (CCI), hides malicious instructions inside encrypted content. These instructions are treated as trusted context when Copilot CLI decrypts the content using its own code-execution environment, allowing them to influence what the agent does next.