Critical Malicious Code Vulnerability in chai-sub Package
Summary
MAL-2026-588: Malicious code in chai-sub (npm). Affected versions are not published. No fix is published. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
The chai-sub package is an npm library that extends the Chai assertion library, allowing for more expressive assertions in JavaScript testing. It is commonly used in conjunction with testing frameworks to enhance the readability and maintainability of test cases. However, this package has been compromised, leading to significant security concerns.
Vulnerability Detail
The vulnerability stems from the presence of malicious code within the chai-sub package, which has been identified as a serious threat. Any system running this package is considered fully compromised, potentially allowing attackers to access sensitive information such as secrets and keys. The malicious code can execute arbitrary commands, leading to further exploitation of the affected system. Users are advised to treat any computer with this package installed as compromised and take immediate action.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall chai-subIf 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 →
Workaround
Currently, there are no effective workarounds to mitigate the risks associated with the chai-sub package. The only recommended action is to uninstall the package and secure your environment.
Conclusion
The discovery of malicious code in the chai-sub package poses a significant threat to users. Immediate action is required to uninstall the package and secure any sensitive information. Regular monitoring of dependencies using tools like Vulert can help prevent future vulnerabilities.
See every vulnerability recorded for chai-sub →
FAQ
Immediately uninstall the chai-sub package and rotate any sensitive information stored on the affected machine.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
No, there is currently no patched version available for the chai-sub package. The only solution is to uninstall it.
Failing to address this vulnerability can lead to unauthorized access to sensitive data and complete control of your system by malicious actors.
Vulert monitors and alerts for open-source vulnerabilities in your software using just the package-lock.json file, providing real-time insights without requiring code access.
