Chrome Extensions’ Critical Flaws Let Attackers Easily Compromise Millions of Browsers

Cybersecuritynews •Abinaya • June 19, 2026

Critical security flaws discovered in widely used Chrome extensions SiderAI and MaxAI are putting millions of users at risk, enabling attackers to fully compromise browser sessions and potentially access sensitive data across websites and local systems. Security researchers at Rebora Security uncovered vulnerabilities dubbed “Spyder” and “MaXSS” affecting AI-powered “agentic side panel” extensions. These tools, […]

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Critical Flaws in Chrome Extensions Expose Millions to Browser Compromise Security researchers at Rebora Security have identified critical vulnerabilities in popular Chrome extensions SiderAI and MaxAI, affecting millions of users. The vulnerabilities, named 'Spyder' and 'MaXSS', allow attackers to fully compromise browser sessions, potentially accessing sensitive data. These extensions, which have over 10 million installations, are designed to assist users with AI-powered features. The flaws pose a significant risk as they transform these tools into vectors for malicious exploitation. Users of Chrome and other Chromium-based browsers are particularly at risk. Immediate action is recommended to mitigate potential threats. The vulnerabilities have been disclosed as part of ongoing security research efforts. 2 sources 68

Chrome Extensions’ Critical Flaws Let Attackers Easily Compromise Millions of Browsers

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