# MAL-2026-13624: Malicious code in @depup/memfs (npm)


- **Type:** Malicious package
- **Package:** `@depup/memfs` (npm)
- **Published:** 7 Aug 2026

## What is MAL-2026-13624?

MAL-2026-13624 is a malicious package in @depup/memfs, published on 7 Aug 2026. 

### Official description

This package is an automated 'DepUp' republish of memfs whose lib/index.js and lib/index.d.ts have been stripped of the upstream source and rewritten to require nine '@jsonjoy.com/fs-*' packages (fs-node, fs-core, fs-node-utils, fs-fsa, fs-node-to-fsa, fs-fsa-to-node, fs-print, fs-snapshot, fs-node-builtins), all pinned to 4.67.0 — a version tag that matches memfs itself rather than any real release history of those names. Upstream memfs bundles its own source and does not depend on these packages. The republished lib/index.js contains only require() calls to the '@jsonjoy.com/fs-*' names, so installing this package and importing memfs resolves and executes whatever code is published under those names at 4.67.0. The package.json 'depup.changes' metadata also records bumping @jsonjoy.com/json-pack and @jsonjoy.com/util from ^1.11.0/^1.9.0 to ^18.28.0, non-contiguous jumps well beyond the real published range of those libraries, consistent with steering the resolver toward attacker-published versions. Installing or requiring @depup/memfs pulls in and runs code from a set of newly-introduced dependency names controlled by the republisher, with no lifecycle hook needed — a dependency-chain dropper shape via a memfs lookalike.

## What should I do about MAL-2026-13624?

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-2026-13624 is a malicious package: @depup/memfs (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-2026-13624/ (Markdown: https://insights.sbomify.com/MAL-2026-13624/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13624

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13624/
Summaries are generated and may contain mistakes; the official description above is the record.