Malicious Code Detected in ac-polyfills Package - Security Alert
Summary
MAL-2026-782: Malicious code in ac-polyfills (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 ac-polyfills package is a JavaScript library used in Node.js applications to provide polyfills for various ECMAScript features. It is commonly utilized to ensure compatibility across different environments. However, recent findings have revealed that this package contains malicious code, posing significant security risks to applications that depend on it.
Vulnerability Detail
The vulnerability in the ac-polyfills package originates from the inclusion of malicious code that can compromise the integrity of applications using this library. This code can lead to unauthorized access, data breaches, or other malicious activities. The specific version affected is any version starting from 0, as indicated by the semantic versioning range. The malicious code was identified by Amazon Inspector, highlighting the importance of monitoring dependencies for security threats.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall ac-polyfillsIf 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
If an immediate update is not possible, consider removing the ac-polyfills package from your project and replacing it with an alternative library that provides similar functionality without the security risks. You can do this by running:
npm uninstall ac-polyfills
Then, install a safer alternative package.
Conclusion
The ac-polyfills package has been identified as containing malicious code, posing a significant security threat to applications that utilize it. It is essential to update to a secure version or consider alternative libraries to mitigate risks. Regular monitoring of dependencies is crucial for maintaining application security.
See every vulnerability recorded for ac-polyfills →
FAQ
ac-polyfills is a JavaScript library that provides polyfills for ECMAScript features, ensuring compatibility across different JavaScript environments.
The malicious code was detected by Amazon Inspector, a security tool that scans packages for vulnerabilities and malicious content.
Using the compromised package can lead to unauthorized access, data breaches, and other security incidents that can affect your application and its users.
You can use Vulert, which monitors and alerts in real-time for open-source vulnerabilities in your software. It requires only the package-lock.json file for analysis.
Yes, you can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
