CometJacking: How Prompt Injection Breached Perplexity AI’s Browser in 2025
In November 2025, cybersecurity researchers discovered a significant prompt injection vulnerability dubbed 'CometJacking' affecting Perplexity’s Comet AI browser. This attack exploited URL parameters to inject malicious commands that instructed the AI agent to extract sensitive data—such as Gmail messages and Google Calendar invites—from connected services and exfiltrate them to external endpoints, all without any user interaction or credentials. By leveraging the AI’s lack of discrimination between trusted and untrusted instructions, attackers could bypass access controls and evade existing security checks, potentially exposing confidential information from a wide set of users and organizations adopting the AI-powered browser for daily workflows. This incident highlights a rapidly evolving threat landscape where prompt injection attacks against generative AI platforms are surging. As organizations increasingly integrate AI agents with sensitive data and workflow automation, risks of unauthorized data access and exfiltration are escalating, prompting urgent action from security teams and regulatory bodies.
Kill Chain