[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$f9EfBN5iqnoTaxoWpkqL4iFgRnspfRt-gTdUHYP62hqs":3},{"article":4,"iocs":52},{"id":5,"title":6,"slug":7,"summary":8,"ai_summary":9,"brief":10,"full_text":11,"url":12,"image_url":13,"published_at":14,"ingested_at":15,"relevance_score":16,"entities":17,"category_id":31,"category":32,"article_tags":36},"780c4736-e0ba-487b-bcc6-927d2b3e3dc4","Vulnerability in Claude Extension for Chrome Exposes AI Agent to Takeover","vulnerability-in-claude-extension-for-chrome-exposes-ai-agent-to-takeover-78ba37","Lax extension permissions and improper trust implementation allow attackers to inject prompts in the Claude Chrome extension. The post Vulnerability in Claude Extension for Chrome Exposes AI Agent to Takeover appeared first on SecurityWeek.","LayerX discovered ClaudeBleed, a vulnerability in Anthropic's Claude Chrome extension that allows attackers to take over the AI agent through lax permissions and improper trust implementation. By creating a malicious extension, attackers can inject prompts, bypass user confirmations via DOM manipulation, and exfiltrate data from Gmail, GitHub, and Google Drive. Anthropic's partial patch only addressed the issue in standard mode, leaving privileged mode exploitable without user notification.","ClaudeBleed vulnerability in Claude Chrome extension allows attackers to hijack AI agent via prompt injection.","A vulnerability in the Claude extension for Chrome could allow attackers to take over the AI agent and abuse it for information theft, cybersecurity firm LayerX reports. The flaw, dubbed ClaudeBleed, is a combination of lax permissions, where any Chrome extension can run commands in Claude in Chrome, and poorly implemented trust in the origin of the command, not the execution context. According to LayerX, the main issue is that the Claude extension allows interaction with any script running in the origin browser, without verifying its owner. “As a result, any extension can invoke a content script (which does not require any special permissions) and issue commands to the Claude extension,” the company explains. Claude in Chrome, it says, trusts the origin of the execution, which is claude.ai, and not the execution context, thus allowing any JavaScript running in the origin to issue privileged commands. This allows an attacker to create an extension with a declared content script and configured to run in the Main world, thus ensuring the script is executed as part of the page, and send a message to the Claude extension, which trusts the sender because it runs in claude.ai.Advertisement. Scroll to continue reading. Because a message handler in Claude in Chrome accepts and forwards arbitrary prompts, the attacker can perform remote prompt injection and control the AI agent’s actions. While Claude enforces user confirmation for sensitive actions, as well as policies that prevent certain actions, and makes decisions based on certain inputs, LayerX discovered that the attacker’s script could bypass these protections. The company was able to forge user approval by repeatedly sending a confirmation message and relied on Document Object Model (DOM) manipulation to dynamically modify UI elements and alter Claude’s perception of the actions. It was also able to gain visibility into command execution through repeated triggering of the action and by observing the effects. “This vulnerability effectively breaks Chrome’s extension security model by allowing a zero-permission extension to inherit the capabilities of a trusted AI assistant,” LayerX says. This attack chain, the company says, allows an attacker to weaponize Claude to exfiltrate data from Gmail, GitHub, or Google Drive, as well as to send emails, delete data, and share documents on behalf of the user. When notified of the issue, Anthropic told LayerX it was working on a patch, but the fix only partially addressed the underlying vulnerability, through “internal security checks to prevent extensions running in ‘standard’ mode from executing remote commands”. Because the root cause of the weakness was not addressed, an attacker can simply switch the extension to ‘privileged’ mode and bypass the fix. The user is never notified or asked to approve the switch, LayerX says. Related: Claude Code OAuth Tokens Can Be Stolen Through Stealthy MCP Hijacking Related: Claude AI Guided Hackers Toward OT Assets During Water Utility Intrusion Related: Anthropic Unveils Claude Security to Counter AI-Powered Exploit Surge Related: Claude Code, Gemini CLI, GitHub Copilot Agents Vulnerable to Prompt Injection via Comments Written By Ionut Arghire Ionut Arghire is an international correspondent for SecurityWeek. More from Ionut Arghire Vendor Says Daemon Tools Supply Chain Attack ContainedCisco Patches High-Severity Vulnerabilities in Enterprise ProductsGemini CLI Vulnerability Could Have Led to Code Execution, Supply Chain AttackHerd Security Raises $3 Million for AI-Powered Training PlatformIranian APT Intrusion Masquerades as Chaos Ransomware AttackSophisticated Quasar Linux RAT Targets Software DevelopersGovernment, Scientific Entities Hit via Daemon Tools Supply Chain AttackOracle Debuts Monthly Critical Security Patch Updates Latest News Ransomware Group Takes Credit for Trellix HackIvanti Patches EPMM Zero-Day Exploited in Targeted AttacksWorries About AI’s Risks to Humanity Loom Over the Trial Pitting Musk Against OpenAI’s LeadersPalo Alto Zero-Day Exploited in Campaign Bearing Hallmarks of Chinese State HackingBoost Security Raises $4 Million for SDLC Defense PlatformClaude Code OAuth Tokens Can Be Stolen Through Stealthy MCP HijackingChrome 148 Rolls Out With 127 Security FixesAttackers Could Exploit AI Vision Models Using Imperceptible Image Changes Trending Daily Briefing NewsletterSubscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts. Webinar: ROSI for CPS Security Programs May 13, 2026 In cyber-physical systems (CPS), just one hour of downtime can outweigh an entire annual security budget. Learn how to master the Return on Security Investment (ROSI) to align security goals with the bottom-line priorities. Register Virtual Event: Threat Detection and Incident Response Summit May 20, 2026 Delve into big-picture strategies to reduce attack surfaces, improve patch management, conduct post-incident forensics, and tools and tricks needed in a modern organization. Register People on the MoveSumo Logic has named Jeremy Powell as CISO and Ben Cody as SVP of Product Management.Bitdefender has appointed Frank Koelmel as Chief Revenue Officer of Business Solutions Group.John Hernandez has joined BlueVoyant as Chief Executive Officer.More People On The MoveExpert Insights The Mythos Moment: Enterprises Must Fight Agents with Agents Only with the right platform and an agentic, AI-driven defense, will enterprises be able to protect themselves in the agentic era. (Etay Maor) Why Cybersecurity Must Rethink Defense in the Age of Autonomous Agents From autonomous code generation to decision-making systems that initiate actions without human intervention, the industry is entering a new phase. (Torsten George) Government Can’t Win the Cyber War Without the Private Sector Securing national resilience now depends on faster, deeper partnerships with the private sector. (Steve Durbin) The Hidden ROI of Visibility: Better Decisions, Better Behavior, Better Security Beyond monitoring and compliance, visibility acts as a powerful deterrent, shaping user behavior, improving collaboration, and enabling more accurate, data-driven security decisions. (Joshua Goldfarb) The New Rules of Engagement: Matching Agentic Attack Speed The cybersecurity response to AI-enabled nation-state threats cannot be incremental. It must be architectural. (Nadir Izrael) Flipboard Reddit Whatsapp Whatsapp Email","https:\u002F\u002Fwww.securityweek.com\u002Fvulnerability-in-claude-extension-for-chrome-exposes-ai-agent-to-takeover\u002F","https:\u002F\u002Fwww.securityweek.com\u002Fwp-content\u002Fuploads\u002F2024\u002F06\u002FChrome.jpeg","2026-05-08T06:53:36+00:00","2026-05-08T08:00:31.40347+00:00",9,[18,21,24,26,28],{"name":19,"type":20},"Claude Chrome Extension","product",{"name":22,"type":23},"Anthropic","vendor",{"name":25,"type":20},"Chrome",{"name":27,"type":23},"LayerX",{"name":29,"type":30},"Chrome Extension Security Model","technology","80544778-fabb-4dcd-aa35-17492e5dcf4f",{"id":31,"icon":33,"name":34,"slug":35},null,"Vulnerabilities","vulnerabilities",[37,42,47],{"category":38},{"id":39,"icon":33,"name":40,"slug":41},"02371804-cf6d-4449-98de-f1a2d4d9b266","Tools","tools",{"category":43},{"id":44,"icon":33,"name":45,"slug":46},"2c8f44d4-b56e-47cf-9677-04f22c9ee78d","Identity & Access","identity-access",{"category":48},{"id":49,"icon":33,"name":50,"slug":51},"839da5c1-3c34-47e2-9499-f7201640e3ac","AI Security","ai-security",[53],{"type":54,"value":55,"context":56},"malware","ClaudeBleed","Vulnerability identifier for Claude Chrome extension privilege escalation and prompt injection attack"]