Google Calendar Vulnerability Lets Hackers Exploit Gemini AI to Leak Private Meeting Data

A simple Google Calendar invite exposed a significant new vulnerability in the way artificial intelligence (AI) capabilities are utilized today. What appeared to be a routine meeting invite was actually a clever way to capture confidential information without users clicking or approving anything. This instance demonstrates how AI-powered things can be misused in ways that many people do not expect.

Miggo's security researchers uncovered a flaw in how Google Gemini, Google's AI assistant, interacts with Google Calendar. Gemini is intended to help users manage their calendars by reading calendar events, such as titles, dates, and participants. However, researchers discovered that this useful function may be used to compromise privacy.

Attackers were able to hide malicious instructions inside the description of a calendar event. This technique is known as a prompt injection. The text looked harmless and raised no warnings. It stayed inactive until the user asked Gemini a simple question like, “Am I free on Saturday?” When Gemini scanned the calendar to answer, it unknowingly followed the hidden instruction. As a result, Gemini summarized private meetings for that day, established a new calendar event with this sensitive information, and deceptively informed the user that the time slot was available. This new event made the private meeting details available to the attacker. The person never clicked anything or provided permission, but their information was leaked.

This attack is different from traditional hacking methods. Most application security systems look for harmful code patterns like SQL injections or suspicious scripts. In this case, the language itself was the weapon. The words sounded normal, but Gemini’s understanding of their meaning caused the breach. This is called a semantic attack, and current security tools struggle to detect it.

Experts say this incident highlights a major shift in cybersecurity. AI systems like Gemini act as powerful application layers with access to sensitive data. This means companies must rethink security strategies and focus on understanding intent, context, and AI behavior in real time. Google has fixed the issue after it was responsibly reported. Still, this case serves as a strong warning. As AI tools become part of everyday apps, protecting user data will require smarter, AI-aware security measures to stay ahead of new threats.

Information referenced in this article is from GB Hackers