Gmail hit by AI prompt injection attack via calendar
Google has confirmed a security vulnerability involving a new AI-driven attack that can compromise Gmail accounts.
The company noted that the threat “is not specific to Google” and highlights the need for stronger defenses against prompt injection attacks.
How the prompt injection attack works
The attack uses malicious instructions hidden inside seemingly harmless items like emails, attachments, or calendar invitations. While these instructions are invisible to a human user, an AI assistant can read and execute them.
Researcher Eito Miyamura demonstrated the vulnerability in a video posted on X.
We got ChatGPT to leak your private email data. All you need? The victim’s email address. AI agents like ChatGPT follow your commands, not your common sense… with just your email, we managed to exfiltrate all your private information.
We got ChatGPT to leak your private email data 💀💀
All you need? The victim’s email address. ⛓️💥🚩📧
On Wednesday, @OpenAI added full support for MCP (Model Context Protocol) tools in ChatGPT. Allowing ChatGPT to connect and read your Gmail, Calendar, Sharepoint, Notion,… pic.twitter.com/E5VuhZp2u2
— Eito Miyamura | 🇯🇵🇬🇧 (@Eito_Miyamura) September 12, 2025
The attack can be triggered by a specially crafted calendar invite that the user does not even need to accept. When the user asks their AI assistant to perform a routine task like checking their calendar, the AI reads the hidden command in the invite. The malicious command then instructs the AI to search the user’s private emails and send the data to the attacker.
How to protect your account and Google’s response
Google previously warned about this type of threat in June, stating that instructions embedded in documents or calendar invites could instruct AI to “exfiltrate user data or execute other rogue actions.” The company is now implementing defenses and advising users on how to protect themselves.
- Enable the “known senders” setting in Google Calendar: Google states this is an effective way to prevent malicious invites from automatically appearing on your calendar. The attack is less likely to work unless the user has previously interacted with the attacker or changed this default setting.
- Google is training its AI models to resist these attacks: The company says its training with adversarial data has “significantly enhanced our defenses against indirect prompt injection attacks in Gemini 2.5 models.”
- New detection models are being deployed: Google is rolling out proprietary machine learning models that can detect and neutralize malicious prompts within emails and files before they are executed.
Remember, AI might be super smart, but can be tricked and phished in incredibly dumb ways to leak your data.
Featured image credit
FAQs
Frequently Asked Questions
What is a Premium Domain Name? A premium domain name is the digital equivalent of prime real estate. It’s a short, catchy, and highly desirable web address that can significantly boost your brand's impact. These exclusive domains are already owned but available for purchase, offering you a shortcut to a powerful online presence. Why Choose a Premium Domain? Instant Brand Boost: Premium domains are like instant credibility boosters. They command attention, inspire trust, and make your business look established from day one. Memorable and Magnetic: Short, sweet, and unforgettable - these domains stick in people's minds. This means more visitors, better recall, and ultimately, more business. Outshine the Competition: In a crowded digital world, a premium domain is your secret weapon. Stand out, get noticed, and leave a lasting impression. Smart Investment: Premium domains often appreciate in value, just like a well-chosen piece of property. Own a piece of the digital world that could pay dividends. What Sets Premium Domains Apart? Unlike ordinary domain names, premium domains are carefully crafted to be exceptional. They are shorter, more memorable, and often include valuable keywords. Plus, they often come with a built-in advantage: established online presence and search engine visibility. How Much Does a Premium Domain Cost? The price tag for a premium domain depends on its desirability. While they cost more than standard domains, the investment can be game-changing. Think of it as an upfront cost for a long-term return. BrandBucket offers transparent pricing, so you know exactly what you're getting. Premium Domains: Worth the Investment? Absolutely! A premium domain is more than just a website address; it's a strategic asset. By choosing the right premium domain, you're investing in your brand's future and setting yourself up for long-term success. What Are the Costs Associated with a Premium Domain? While the initial purchase price of a premium domain is typically higher than a standard domain, the annual renewal fees are usually the same. Additionally, you may incur transfer fees if you decide to sell or move the domain to a different registrar. Can I Negotiate the Price of a Premium Domain?
In some cases, it may be possible to negotiate the price of a premium domain. However, the success of negotiations depends on factors such as the domain's demand, the seller's willingness to negotiate, and the overall market conditions. At BrandBucket, we offer transparent, upfront pricing, but if you see a name that you like and wish to discuss price, please reach out to our sales team.
How Do I Transfer a Premium Domain?
Transferring a premium domain involves a few steps, including unlocking the domain, obtaining an authorization code from the current registrar, and initiating the transfer with the new registrar. Many domain name marketplaces, including BrandBucket, offer assistance with the transfer process.
