Cursor on October 29, 2026 disclosed a security incident involving a maliciously modified version of the Anthropic.claude-code extension in its VS Code extension Marketplace. The company said the package was not developed by Anthropic and that it ran code attempting to install a persistent SSH backdoor. At most 5,000 users were affected. In a security notice, the company said it will reach out to affected users directly. The malicious package, version 2.1.313 of Anthropic’s Claude Code…