
Zero-Click Prompt Injection in Claude's Chrome Extension: One Iframe, No Warning, Everything Gone
The attack required no action from the victim. Visit a page. Leave. By the time the browser tab closed, the extension had already talked to Claude, exported chat history, read Gmail, and potentially sent an email under your name. Patched in Claude Chrome extension v1.0.41. Here is how the chain worked. The Attack Chain The Claude Chrome extension trusted any page on *.claude.ai to send it messages. That wildcard, every subdomain under claude.ai, is where the attack found its entry point. ...

