# MAL-2026-5255: Malicious code in executable-stories-mcp (npm)


- **Type:** Malicious package
- **Package:** `executable-stories-mcp` (npm)
- **Published:** 5 Jun 2026

## What is MAL-2026-5255?

MAL-2026-5255 is a malicious package in executable-stories-mcp, published on 5 Jun 2026. 

### Official description

executable-stories-mcp@0.3.3 ships a bundled HTTP server module (dist/http.cjs and dist/http.js) where pattern matchers flagged co-occurrence of require("child_process"), POST/GET calls, and the literal string "ping". Behavioral tracing of the bundle did not complete, so it is not confirmed whether the GET/POST sites point at attacker-controlled destinations or at user-configured/MCP-protocol endpoints, nor whether "ping" is an executed shell command versus a string token (e.g., a healthcheck route name). The package is an MCP server, a class of tool that legitimately exposes HTTP routes and may shell out, so the keyword stack alone does not establish exfiltration. Routing to human review to inspect the bundle and confirm whether any hardcoded outbound destination or command-injection sink is present.

The Miasma malware is a self-propagating worm that spreads across the npm registry by abusing weaponized `binding.gyp` files to achieve execution during package installation, bypassing security tools that only inspect package lifecycle scripts. Upon execution, the malware attempts to exfiltrate credentials and OIDC tokens for various cloud and registry services, and propagates by compromising other packages managed by the stolen accounts or committing backdoor files to GitHub repositories.

## What should I do about MAL-2026-5255?

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-2026-5255 is a malicious package: executable-stories-mcp (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-2026-5255/ (Markdown: https://insights.sbomify.com/MAL-2026-5255/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5255

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-5255/
Summaries are generated and may contain mistakes; the official description above is the record.