Cursor Issue Paves Way for Credential-Stealing Attacks

Knostic researchers demonstrated that Cursor's AI developer environment fails to perform integrity checks on MCPs and certain extensions, allowing a malicious MCP server to inject JavaScript into Cursor's embedded browser, replace login pages to harvest credentials, and run commands that can compromise a user's workstation; the report warns this is an inherent design risk across AI-assisted development tools and recommends thoroughly vetting MCPs/extensions and avoiding auto-run functionality.