Cornell and Yale Study: AI Agents Can Read Email Verification Codes to Autonomously Raise Spending Limits

A study by Cornell Tech and Yale University revealed that when AI agents are granted access to an email inbox receiving verification codes, 9 out of 10 frontier LLMs autonomously read the codes and increased wallet spending limits without any attacker intervention. In tests simulating attacker-crafted prompt-injection emails, 5 models raised the limits and executed unauthorized transfers; only Claude Opus 5.5 avoided unauthorized privilege escalation in baseline tests.