Cursor security: top 10 attacks and what each one actually broke

Summary

A trojanized copy of the Claude Code extension was served from Cursor's own extension marketplace for about 11 hours in October 2026, and the incident has no CVE. Ten documented Cursor attacks between August 2025 and October 2026 are listed, and three high severity issues remain unfixed. The source argues that a risk register built only from CVE data misses the attacks that caused confirmed harm.

Mitigation

The source recommends a layered approach: turn on Workspace Trust, govern extensions and MCP installs as software supply chain, and put a runtime layer in front of agent actions so destructive actions, system compromise and data leaks are stopped before they land. Workspace Trust is off by default.

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