# MAL-2026-13369: Malicious code in kepler (npm)


- **Type:** Malicious package
- **Package:** `kepler` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-4h56-85v2-4qj4

## What is MAL-2026-13369?

MAL-2026-13369 is a malicious package in kepler, published on 5 Aug 2026. 

### Official description

kepler@2.0.999 declares its only runtime dependency, flag-serial-object-syntax, as an HTTP URL to a third-party host (https://artifacts.yosiroute.com/npm/flag-serial-object-syntax) rather than a version resolved from the npm registry, and the shrinkwrap marks that dependency with hasInstallScript: true. Running `npm install kepler` fetches an unpinned, unverified tarball from artifacts.yosiroute.com and executes its lifecycle scripts on the installer's machine. The URL carries no version and no integrity metadata, so its contents can change at any time under the third-party host's control. The kepler package itself has placeholder metadata (author `Package Registry`, repository `github.com/example/...`) unrelated to the yosiroute.com host, and ships no first-party code that would justify sourcing a dependency off-registry. The dependency-tree-hijack shape — an off-registry, mutable, install-scripted tarball pulled in transitively — means any code the operator of artifacts.yosiroute.com serves runs with the privileges of the installer on `npm install`.

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-2026-13369?

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-2026-13369 is a malicious package: kepler (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-2026-13369/ (Markdown: https://insights.sbomify.com/MAL-2026-13369/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13369

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13369/
Summaries are generated and may contain mistakes; the official description above is the record.