SneakPeek exploit chain found in Claude Code Desktop preview pane

Noma Labs disclosed SneakPeek, a flaw in Claude Code Desktop's preview pane: HTML files over 256KB loaded as file:// URLs without CSP, letting scripts run and read local files like SSH keys and AWS, npm and GitHub tokens. Anthropic rated it CVSS 8.7 and fixed it on August 17 in Claude Desktop 1.30096.1.

• Files under 256KB used data: URLs with CSP; larger ones used file:// without it
• The exploit read SSH keys, AWS, npm and GitHub tokens, and Kubernetes data
• The first patch was bypassed via fetch() in a blob: Web Worker
• The complete fix shipped August 17 in Claude Desktop 1.30096.1