Claude Desktop Silently Installs Browser Extension Bridges: Privacy Violation
Claude Desktop Silently Installs Browser Extension Bridges: Privacy Violation is a high-severity security issue in Claude Desktop, an AI agent. Affected: Claude Desktop (macOS, all versions with browser automation).
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Key facts
- ID
claude-desktop-silently-installs-browser-extension-bridges-privacy- Severity
- high
- Attack type
- Other
- Component
- Claude Desktop · AI agent
- Known exploited
- No known exploitation
- Published
- Last verified
What is this vulnerability?
Security researcher Alexander Hanff discovered that Claude Desktop silently installs Native Messaging host manifests into seven Chromium browsers (Chrome, Brave, Edge, Arc, Vivaldi, Chromium, Opera) on first launch, including browsers not installed on the machine. The manifests pre-authorize browser extensions to access authenticated sessions and DOM data. Files are rewritten on every app launch, preventing persistent removal. Anthropic's own testing showed the feature is vulnerable to prompt injection roughly 25% of the time.
Affected versions
| Affected | Fixed in |
|---|---|
Claude Desktop (macOS, all versions with browser automation) | No fixed version listed |
Am I affected by this vulnerability?
You are affected if you run Claude Desktop (macOS, all versions with browser automation).
How do I fix it?
Audit for com.anthropic.claude_browser_extension.json in browser NativeMessagingHosts directories. Remove unwanted manifests. Monitor for reinstallation after Claude Desktop launches. Consider blocking Claude Desktop browser automation via MDM policy.
How do I find every machine running Claude Desktop?
Anomity inventories the AI agents, MCP servers, IDE extensions and skills on each developer device, so you can see which machines run Claude Desktop and which version, then enforce a policy on it.