# MAL-2026-12428: Malicious code in rollup-packages-node-polyfills (npm)


- **Type:** Malicious package
- **Package:** `rollup-packages-node-polyfills` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-gp6f-mxh4-x3mh

## What is MAL-2026-12428?

MAL-2026-12428 is a malicious package in rollup-packages-node-polyfills, published on 5 Aug 2026. 

### Official description

The package is a typosquat of `rollup-plugin-polyfill-node`. On `require()` of the main entry (`dist/index.js`), a base64-encoded command `npm install cors-update --no-save --silent --no-audit --no-fund` is decoded and passed to `child_process.spawn` with `stdio:'ignore'` and `windowsHide:true`. When the install child exits, the code then base64-decodes the module name `cors-update`, dynamically `require`s it, and invokes `.getPlugin()()`, executing whatever code that separately-published package ships. The command string and the target module name are both stored as base64 literals to evade plain-text scanners. The package's advertised purpose (a Rollup Node polyfills plugin) does not require installing or executing any other npm package at import 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-2026-12428?

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-2026-12428 is a malicious package: rollup-packages-node-polyfills (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-2026-12428/ (Markdown: https://insights.sbomify.com/MAL-2026-12428/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12428

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12428/
Summaries are generated and may contain mistakes; the official description above is the record.