# MAL-2026-6294: Malicious code in cue-mcp (npm)


- **Type:** Malicious package
- **Package:** `cue-mcp` (npm)
- **Published:** 23 Jun 2026

## What is MAL-2026-6294?

MAL-2026-6294 is a malicious package in cue-mcp, published on 23 Jun 2026. 

### Official description

The package's postinstall.js script runs automatically on `npm install` and collects host identifying data (os.hostname()) along with process environment variables (process.env), then transmits the data over HTTPS. This shape — system-information harvesting at install time and outbound network transmission via the `https` module — is a classic install-time exfiltration pattern. There is no legitimate purpose served by reading the installer's environment variables and hostname during postinstall for a package of this kind. Environment variables on developer and CI machines routinely contain credentials (NPM_TOKEN, GITHUB_TOKEN, AWS keys, CI secrets), so this beacon constitutes credential exfiltration risk against any system that installs the package.

## What should I do about MAL-2026-6294?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-6294 is a malicious package: cue-mcp (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-6294/ (Markdown: https://insights.sbomify.com/MAL-2026-6294/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6294

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6294/
Summaries are generated and may contain mistakes; the official description above is the record.