CVE-2015-8857: Incorrect Handling of Non-Boolean Comparisons During Minification in uglify-js

uglify-js Updated 02 Oct 2025

Summary

24/10/2017

Disclosed on

CVE-2015-8857

CVE

Yes i

Fix available

Critical

Severity

9.8

CVSS Score

CVE-2015-8857: Incorrect Handling of Non-Boolean Comparisons During Minification in uglify-js. Affects uglify-js versions < 2.4.24. Fixed in 2.4.24. How to fix ↓

Also tracked for

uglifyjs · Debian:11

The same CVE-2015-8857 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.

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Background

The uglify-js package is a JavaScript parser, minifier, and compressor. It is commonly used to reduce the size of JavaScript files for improved performance. However, versions prior to 2.4.24 are vulnerable to a specific issue that can alter the functionality of crafted JavaScript code after minification.

Vulnerability Detail

The vulnerability in uglify-js arises from incorrect handling of non-boolean comparisons during the minification process. This can lead to unexpected behavior in the minified code, potentially introducing security vulnerabilities or causing the code to behave differently than intended. The impact of this vulnerability can vary depending on the specific code being minified and the context in which it is used.

How To Fix

Minimum fixed version

2.4.24

This is the first release that contains the fix.

npm install uglify-js@2.4.24

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Workaround

There is no specific workaround mentioned for this vulnerability.

Conclusion

The vulnerability in uglify-js can lead to altered functionality of minified JavaScript code. To mitigate this issue, it is recommended to upgrade to version 2.4.24 or higher. For further support on vulnerability remediation, please contact DevNack.com.

See every vulnerability recorded for uglify-js →