Software supply chain lesson
A package name is not provenance
Cursor said a malicious build of its Marketplace package named Anthropic.claude-code 2.1.313 was available for about eleven hours on 29 October 2026. Cursor said that build was not developed by Anthropic, removed it, rebuilt its marketplace and rotated keys. The practical lesson is to verify the exact source, publisher, version and integrity evidence for extensions and tools before they reach an endpoint or an agent workflow.
Early reports also mentioned Open VSX. Later researcher reporting challenged that distribution description, so this article does not treat the Open VSX scope as established fact.
