As the browser agent helps you get more done, it also becomes a higher-value target of adversarial attacks. This makes AI security especially important. Long before we launched ChatGPT Atlas, we’ve been continuously building and hardening defenses against emerging threats that specifically target this new “agent in the browser” paradigm. Prompt injection⁠ is one of the most significant risks we actively defend against to help ensure ChatGPT Atlas can operate securely on your behalf.

As part of this effort, we recently shipped a security update to Atlas’s browser agent, including a newly adversarially trained model and strengthened surrounding safeguards. This update was prompted by a new class of prompt-injection attacks uncovered through our internal automated red teaming.

In this post, we explain how prompt-injection risk can arise for web-based agents, and we share a rapid response loop we’ve been building to continuously discover new attacks and ship mitigations quickly—illustrated by this recent security update.

We view prompt injection as a long-term AI security challenge, and we’ll need to continuously strengthen our defenses against it (much like ever-evolving online scams that target humans). Our latest rapid response cycle is showing early promise as a critical tool on that journey: we’re discovering novel attack strategies internally before they show up in the wild. Our long-term vision is to fully leverage (1) our white-box access to our models, (2) deep understanding of our defenses, and (3) compute scale to stay ahead of external attackers—finding exploits earlier, shipping mitigations faster, and continuously tightening the loop. Combined with frontier research on new techniques to address prompt injection and increased investment in other security controls, this compounding cycle can make attacks increasingly difficult and costly, materially reducing real-world prompt-injection risk. Ultimately, our goal is for you to be able to trust a ChatGPT agent to use your browser the way you’d trust a highly competent, security-aware colleague or friend.