The serialize-to-js NPM package before version 3.0.1 is vulnerable to Cross-site Scripting (XSS). It does not properly mitigate against unsafe characters in serialized regular expressions. This vulnerability is not affected on Node.js environment since Node.js's implementation of RegExp.prototype.toString() backslash-escapes all forward slashes in regular expressions. If serialized data of regular expression objects are used in an environment other than Node.js, it is affected by this vulnerability.

The deserialize function in serialize-to-js through 1.1.1 allows attackers to cause a denial of service via vectors involving an Immediately Invoked Function Expression "function()" substring, as demonstrated by a "function(){console.log(" call or a simple infinite loop. NOTE: the vendor agrees that denial of service can occur but notes that deserialize is explicitly listed as "harmful" within the README.md file