Malicious Code Detected in rules-playground Package: npm Vulnerability Alert

rules-playground Updated 01 Jan 2026

Summary

01/01/2026
CRITICAL
No i
Critical
Not published

MAL-2026-4: Malicious code in rules-playground (npm). Affects rules-playground versions 0.0.3. No fix is published. How to fix ↓

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Background

The 'rules-playground' package is a Node.js library designed for developers to experiment with various rules and configurations in a controlled environment. It is commonly used in testing and development scenarios. However, version 0.0.3 of this package has been flagged for containing malicious code that communicates with a domain linked to harmful activities, posing a significant security risk to users and their applications.

Vulnerability Detail

The vulnerability in the 'rules-playground' package arises from its communication with a domain associated with malicious activities. This behavior can lead to unauthorized data access, potential data breaches, and exploitation of the affected systems. The origin of this vulnerability was identified by the OpenSSF Package Analysis project, which flagged the package as malicious due to its harmful interactions.

How To Fix

This package is malicious. Remove it and rotate any credentials it could have accessed.

npm uninstall rules-playground

If it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.

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Workaround

As there is no patched version available, the best workaround is to remove the 'rules-playground' package from your project. You can do this by running the command:

npm uninstall rules-playground

Conclusion

The 'rules-playground' package has been identified as malicious due to its harmful communications, posing a significant risk to users. It is crucial to remove this package and monitor for any updates or alternatives. Utilizing tools like Vulert can help in identifying vulnerabilities in your applications effectively.

See every vulnerability recorded for rules-playground →

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FAQ

The 'rules-playground' package is a Node.js library used for testing and experimenting with various rules and configurations in a development environment.

It is considered malicious because it communicates with a domain associated with malicious activities, which can compromise the security of applications using it.

You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. By using the Vulert playground at Vulert Scanner, you can check if your application is affected without needing to sign up.

It is recommended to uninstall the affected version (0.0.3) and look for alternative packages or solutions that do not pose a security risk.

Currently, there is no patched version available for 'rules-playground'. Users should remove the package until a secure version is released.

Sponsored Lume, the Habilume companion Habilume Habit tracker with a companion that grows with you Complete habits, earn Lume Points, and watch your Lume grow as you stay consistent. App Store Google Play

How To Fix

This package is malicious. Remove it and rotate any credentials it could have accessed.

npm uninstall rules-playground

If it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.

Tip — Not sure whether your app is affected? Vulert can check the versions your app actually runs. Scan free →

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