Even more confusing is apparently Cursor Marketplace is OpenVSX + their own proxy to add extensions on top[0], so there are at least two possible cases:
1. The compromised version was present on OpenVSX itself, and Cursor Marketplace proxied to it
2. The compromised version was on Cursor's proxy, not OpenVSX itself
It wasn't on OpenVSX according to https://news.ycombinator.com/item?id=50305148