Claude Code VS Code extension reportedly compromised on Open VSX
Original title: Non-OSS: Claude Code for VS Code extension compromised
The oss-security note says the Microsoft Visual Studio Marketplace copy was allegedly not affected, but the post is incomplete.
Valtteri Vuorikoski posted to oss-security that the official Claude Code for VS Code extension on the Open VSX marketplace was reportedly compromised. Open VSX serves VS Code-derived editors such as Cursor. The post says the copy on the Microsoft Visual Studio Marketplace, which serves apps released by Microsoft, was allegedly not affected. The author frames it as a possible compromise path for open-source maintainers who use Anthropic products. The feed text ends mid-sentence.
Unconfirmed: The compromise is described as reported and alleged, and the post is cut off before any confirmation or remediation.
- Posted October 30 by Valtteri Vuorikoski as a non-open-source item.
- The claimed malicious copy is the official extension on Open VSX.
- Cursor is named as an editor that uses that marketplace.
- No CVE, payload, or confirmed victim is stated in the snippet.
Impact: Possible compromise of projects using the tampered extension
| Product | Affected |
|---|---|
| Anthropic Claude Code for VS Code | official extension on Open VSX; Microsoft marketplace allegedly not affected |
- Vendors
- Anthropic
- Products
- Claude Code for VS CodeCursor
- Organizations
- Open VSX
From the original article
Posted by Valtteri Vuorikoski on Oct 30 Apologies for posting a non-open-source item, but since I get the impression that quite a few open-source maintainers use Anthropic products by various means nowadays, this might be a compromise vector in such projects: Reportedly the official Claude Code for VS Code extension on the Open VSX extension marketplace for VS Code derived editors such as Cursor (but allegedly not…
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