# MAL-2026-13719: Malicious code in commonjs-assertion (npm)


- **Type:** Malicious package
- **Package:** `commonjs-assertion` (npm)
- **Published:** 10 Aug 2026
- **Also known as:** GHSA-mfjj-4625-mpvr

## What is MAL-2026-13719?

MAL-2026-13719 is a malicious package in commonjs-assertion, published on 10 Aug 2026. 

### Official description

Package presents itself as a chai-like assertion library. index.js uses hex-encoded strings to hide the identifiers 'child_process' and 'node' and, on require, unconditionally invokes child_process.spawn to launch a detached, stdio-ignored node child running lib/chai/utils/assertion.js. That file is a heavily obfuscated loader (obfuscator.io rotated string array plus a custom base64/URI decoder) whose decoded logic performs an HTTP GET to a URL reconstructed from the encoded string array and passes the response body to new Function(..., body)(require), granting the fetched remote code full Node access. The assertion.js file is not referenced by chai's real code and is only reachable via the hex-hidden spawn in index.js. Importing the package causes remote code execution on the installer's host at load time.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

## What should I do about MAL-2026-13719?

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-2026-13719 is a malicious package: commonjs-assertion (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-2026-13719/ (Markdown: https://insights.sbomify.com/MAL-2026-13719/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13719

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-13719/
Summaries are generated and may contain mistakes; the official description above is the record.