A researcher identified a significant vulnerability in Anthropic's Claude web_fetch tool that allows for data exfiltration through nested link traversal, bypassing intended safety controls. This exploit enables malicious actors to trick the AI into accessing sensitive user information by navigating through a sequence of dynamically generated URLs on a honeypot site.
Background
Large Language Models often integrate tools like web browsing to enhance functionality, but these integrations introduce complex attack surfaces for prompt injection and data leakage. Recent efforts have focused on sandboxing these tools, yet novel bypass techniques continue to emerge.
- Source
- Simon Willison
- Published
- Jul 15, 2026 at 10:21 PM
- Score
- 9.0 / 10