Critical Malicious Code Vulnerability in samesame Package
Summary
MAL-2025-191419: Malicious code in samesame (npm). Affects samesame versions 1.0.3. 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 samesame package is a Node.js library available on npm, designed to facilitate various functionalities within JavaScript applications. However, it has been compromised, leading to severe security risks. This vulnerability allows malicious actors to exploit the package, potentially compromising the entire system where it is installed.
Vulnerability Detail
The vulnerability stems from a malicious payload introduced by the Sha1-Hulud: The Second Coming NPM worm. This payload is capable of stealing tokens and credentials, publishing them to GitHub, and propagating itself to other NPM packages owned by the user. Additionally, it may establish persistence through GitHub actions and could even destroy the user's home directory. Any system running this package is considered fully compromised, necessitating immediate action.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall samesameIf 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
As a workaround, it is recommended to uninstall the samesame package using the following command: npm uninstall samesame. However, be aware that simply removing the package may not eliminate all malicious software that has been installed as a result of the compromise.
Conclusion
The samesame package has been compromised, leading to a critical vulnerability that can severely impact systems using it. Immediate action is required to mitigate risks, including uninstalling the package and rotating any sensitive credentials. Utilizing tools like Vulert can help monitor for such vulnerabilities in the future.
See every vulnerability recorded for samesame →
FAQ
Immediately uninstall the samesame package and rotate any secrets or keys stored on the compromised system.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Visit Vulert Scanner to check your application without needing to sign up.
Failure to address this vulnerability may result in unauthorized access to sensitive information, loss of data, and further propagation of malicious code.
Regularly monitor your dependencies for vulnerabilities using tools like Vulert and keep your packages updated to the latest secure versions.
While the npm ecosystem is generally reliable, it is essential to remain vigilant and utilize security tools to monitor for potential vulnerabilities.
