I suspect it's still Anthropic who were hacked, because they control OpenVSX account with release privileges.
edit:
Binance confirms my suspicions, via https://www.binance.com/en/square/post/10-30-2026-claude-cod...
The affected Open VSX extension is owned by Anthropic employee Igor Kofman, but it is unclear whether his account or another part of the publishing process was compromised.This could have been avoided by having extensions signed by company doing them with keys and review
Edit: It seems Cursor is claiming the tampered files were only in their mirror.
> Dworken from Anthropic here, that is correct: This only impacted the extension as it was hosted on the Cursor marketplace. It did not impact the official VS Code extension marketplace or OpenVSX. Users of Claude Code on VS Code are not impacted by this issue.
Anthropic's position is seemingly that it was "another part of the publishing process [that] was compromised"
Vibecoders are safu