Critical Malicious Code Vulnerability in syntax-class-properties Package
Summary
MAL-2026-105: Malicious code in syntax-class-properties (npm). Affected versions are not published. No fix is published. How to fix ↓
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Background
The syntax-class-properties package is a JavaScript library used in Node.js applications to enable the use of class properties in syntax. It simplifies the process of defining properties within classes, making it easier for developers to write cleaner and more maintainable code. However, this package has been identified as containing malicious code, posing significant security risks to any system that has it installed.
Vulnerability Detail
The vulnerability originates from the inclusion of malicious code within the syntax-class-properties package. This code can compromise any computer that has the package installed, potentially allowing unauthorized access to sensitive information such as secrets and keys. The ramifications of this vulnerability are severe, as it can lead to full control of the affected system by an external entity. Users are advised to treat any system with this package as fully compromised.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall syntax-class-propertiesIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
There are no effective workarounds for this vulnerability other than removing the package entirely and ensuring that all sensitive information is secured.
Conclusion
The syntax-class-properties package has been identified as containing malicious code that poses a significant security threat. Users are strongly advised to remove the package immediately and secure their systems. Regular monitoring for vulnerabilities, such as using Vulert, can help prevent future issues.
See every vulnerability recorded for syntax-class-properties →
FAQ
You should immediately remove the package and rotate any secrets or keys stored on your system.
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Currently, there is no patched version available. The best course of action is to remove the package.
Failing to address this vulnerability can lead to unauthorized access to sensitive information and complete control of your system by malicious actors.
If your application relies on the syntax-class-properties package, you will need to find an alternative solution or refactor your code to remove the dependency.
