AI TRENDS | Cursor Reports Security Incident Involving Claude Code Extension, Up to 5,000 Users Affected

Cursor said a tampered Claude Code extension accessed through its IDE extension marketplace was involved in a security incident that could affect up to 5,000 users. According to Odaily, Cursor said the malicious extension was not developed by Anthropic and did not affect extensions downloaded from its official website, Grok Bot, Grok, or other SpaceXSI products. Cursor said it closed the extension marketplace that afternoon, worked with service providers to remove the malware, and reopened the marketplace after confirming there was no further risk. It advised affected users to consult its official blog for instructions on finding the malicious package and mitigating potential effects, and asked all customers to update Claude Code for VS Code to version 2.1.314.