How Claude Code’s 256KB blind spot put developers’ secrets in the preview pane

Simply asking Anthropic’s Claude Code to review an HTML file could hand attackers access to a developer’s machine, cloud credentials and software development environment, according to a new Noma Security finding. Noma’s researchers found a vulnerability affecting Anthropic’s Claude Code Desktop app that could allow malicious JavaScript embedded in an HTML file to execute without further user interaction, potentially exposing sensitive host files. The flaw, called SneakPeek, specifically affected the application’s automated preview pane, which renders HTML files generated or modified by Claude.

First reported by CSO Online. This page is a short excerpt; the full text is theirs.