
BragJack Attack Exposes Critical Security Flaws in AI-Powered Browser Agents
In September 2026, security researcher Gal Weizman disclosed BragJack, a novel attack technique that hijacks AI assistants built into popular browsers using malicious extensions. The attack exploited vulnerabilities in five Chromium-based browsers including Google Chrome's Gemini Live, Microsoft Edge, Opera Neon, Perplexity Comet, and Anthropic's Claude extension. By leveraging Chrome's declarativeNetRequest functionality, attackers could manipulate web traffic to privileged browser components, enabling unauthorized access to local files, browsing history, screenshots, and the ability to control AI agents to perform actions on behalf of victims. The research earned over $20,000 in bug bounties and resulted in two CVEs being assigned. This incident highlights the emerging security risks as AI agents become deeply integrated into browsers with elevated privileges, creating new attack vectors that traditional endpoint defenses may not adequately address.
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