CVE-2020-26302

Name: CVE-2020-26302
Creator: NVD / NIST
Published: 2022-12-22T21:15:08.877+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.87%

Last modified Jun 17, 2026

CVE-2020-26302 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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). EPSS estimates a 0.87% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.87%

54.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Is.Js Project	Is.Js	<= 0.9.0

References

https://github.com/arasatasaygin/is.js/issues/320Issue Tracking, Third Party Advisory
https://securitylab.github.com/advisories/GHSL-2020-295-redos-is.jsExploit, Third Party Advisory
https://github.com/arasatasaygin/is.js/issues/320Issue Tracking, Third Party Advisory
https://securitylab.github.com/advisories/GHSL-2020-295-redos-is.jsExploit, Third Party Advisory

Timeline

Published: Dec 22, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26302?

How severe is CVE-2020-26302?

CVE-2020-26302 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.87% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26302?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-26302?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST