# MAL-2026-10151: Malicious code in buffer-util-internal (npm)


- **Type:** Malicious package
- **Package:** `buffer-util-internal` (npm)
- **Published:** 10 Jul 2026

## What is MAL-2026-10151?

MAL-2026-10151 is a malicious package in buffer-util-internal, published on 10 Jul 2026. 

### Official description

Package impersonates Feross Aboukhadijeh's widely-used `buffer` package, copying its author, repository, contributors, and description metadata while publishing under the name `buffer-util-internal`. The main module `index.js` contains a top-level IIFE that base64-decodes a hardcoded URL (decoding to https://www.jsonkeeper.com/b/PT0ON), fetches a JSON document from that anonymous paste host, and passes the response's `content` field directly to `eval`. The destination URL is hidden behind a variable named `tokenStringRe` with a misleading `// Random string to generate strong random value` comment, alongside a second base64 string referencing a sibling paste id. Because the fetched content is attacker-mutable, every consumer that requires this package executes whatever JavaScript the paste host serves at that moment — a full remote code execution primitive on the installer at require time. The package also declares unusual dependencies (axios, execp, request) inconsistent with the legitimate `buffer` package.

## What should I do about MAL-2026-10151?

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-2026-10151 is a malicious package: buffer-util-internal (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-2026-10151/ (Markdown: https://insights.sbomify.com/MAL-2026-10151/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-10151

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-10151/
Summaries are generated and may contain mistakes; the official description above is the record.