Critical Claude for Chrome Flaw Lets Malicious Extensions Read Gmail, Google Docs, and Calendar

Researchers at Manifold disclosed two serious vulnerabilities in Anthropic’s Claude for Chrome extension (v1.0.801.0): a synthetic DOM click injection due to missing event.isTrusted validation that allows any extension with access to claude.ai to trigger allowlisted privileged prompts (potentially exfiltrating Gmail, Docs, Calendar data), and a URL parameter (?skipPermissions=true) that can initialize the panel in an unattended “Act without asking” mode. Manifold assigned CVSS scores of 7.7 (default) and 9.6 (unattended execution), recommended rejecting synthetic events and removing URL-based permission initialization, and noted the issues persist across updates.