### [CVE-2020-26302](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26302)
![](https://img.shields.io/static/v1?label=Product&message=is.js&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=0.9.0%3C%3D%200.9.0%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-400%20Uncontrolled%20Resource%20Consumption&color=brighgreen)

### Description

is.js is a general-purpose check library. Versions 0.9.0 and prior contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). is.js uses a regex copy-pasted from a gist to validate URLs. Trying to validate a malicious string can cause the regex to loop “forever." This vulnerability was found using a CodeQL query which identifies inefficient regular expressions. is.js has no patch for this issue.

### POC

#### Reference
- https://securitylab.github.com/advisories/GHSL-2020-295-redos-is.js
- https://securitylab.github.com/advisories/GHSL-2020-295-redos-is.js

#### Github
- https://github.com/Live-Hack-CVE/CVE-2020-26302