# MAL-2026-6448: Malicious code in bs58-86 (npm)


- **Type:** Malicious package
- **Package:** `bs58-86` (npm)
- **Published:** 25 Jun 2026
- **Also known as:** GHSA-9gvv-wfph-q6rj

## What is MAL-2026-6448?

MAL-2026-6448 is a malicious package in bs58-86, published on 25 Jun 2026. 

### Official description

Package `bs58-86@6.0.1` reproduces the name, README, repository URL (`cryptocoinjs/bs58`), and exported API of the widely-used `bs58` base58 encoding library (>10M downloads/week). The only functional code in `src/cjs/index.cjs` is `require('base62-86x')(ALPHABET)` — instead of depending on the real `base-x` package that genuine `bs58` uses, this package pulls in `base62-86x` (declared as `^5.0.4` in package.json dependencies), an unrelated package controlled by a different publisher. All actual base-x implementation runs out of `base62-86x`, so any developer who installs `bs58-86` thinking it is `bs58` ends up executing whatever `base62-86x` ships, at require time. This is the typosquat-plus-dependency-redirect shape: the lure package is a thin shim whose only effect on the installer is to pull in and execute the redirected dependency.

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-2026-6448?

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-2026-6448 is a malicious package: bs58-86 (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-2026-6448/ (Markdown: https://insights.sbomify.com/MAL-2026-6448/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6448

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-6448/
Summaries are generated and may contain mistakes; the official description above is the record.