A new threat has emerged in the cybersecurity landscape, allowing malicious browser extensions to bypass security controls and run code on users’ computers. This attack vector exploits a previously unknown vulnerability in Chrome’s Claude Dispatch API, which is used to manage cross-domain permissions for browser extensions. As a result, attackers can inject malicious scripts into seemingly innocuous extensions, putting millions of users at risk.
The affected parties are vast and varied, with Chrome users worldwide potentially vulnerable to these attacks. Browser extensions are an integral part of the modern web browsing experience, with many popular add-ons relying on Claude Dispatch to function properly. Unfortunately, this very feature can be exploited by attackers to gain elevated privileges within the browser environment. When a malicious extension is installed, it can use Claude Dispatch to circumvent security controls and execute arbitrary code on the user’s computer.
But how does this work? In essence, Chrome’s Claude Dispatch API is designed to allow extensions to request permissions from other domains, facilitating seamless communication between various components of the web page. However, when an attacker gains control over a trusted extension, they can leverage Claude Dispatch to run malicious scripts with elevated privileges, thereby bypassing traditional security measures.
This vulnerability matters for several reasons. Firstly, the sheer number of users affected is staggering – Chrome has an enormous user base, and many people rely on browser extensions to enhance their browsing experience. Secondly, the attack vector itself is deceptively simple: attackers only need to compromise a single trusted extension to gain access to the entire system. Finally, this vulnerability highlights the ongoing cat-and-mouse game between cybersecurity professionals and malicious actors – as new threats emerge, it becomes increasingly clear that traditional security measures may not be enough to protect against sophisticated attacks.
What can users do to mitigate this risk? For one, they should exercise caution when installing browser extensions, opting only for trusted sources like the Chrome Web Store. Regularly reviewing and updating installed extensions is also crucial – attackers often rely on old or abandoned extensions to gain a foothold within the system. Finally, users should be aware of their browser’s security settings and adjust them according to their specific needs. By staying vigilant and proactive in managing their browser environment, individuals can significantly reduce their exposure to this type of attack.
Source: The Hacker News — 2026-11-06