High

MooTools Regular Expression Denial of Service

  • Disclosed: 03.01.2023
  • Updated: 11.10.2026 10:22

MooTools is a collection of JavaScript utilities for JavaScript developers. All known versions include a CSS selector parser that is vulnerable to Regular Expression Denial of Service (ReDoS). An attack requires that an attacker can inject a string into a CSS selector at runtime, which is quite common with e.g. jQuery CSS selectors. No patches are available for this issue.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package mootools <= 1.5.2 no fix

References

CVSS score 7.5/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-1333, CWE-400
Platform
npm
Package
mootools
Disclosed
03.01.2023
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-v63q-hgqc-qvpg - CC BY 4.0

Vulnerability history: mootools

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
2
First → latest
09.2021 01.2023
Without a fix
2
Exploited in attacks
0

Severity breakdown

  • High 1
  • Medium 1

Disclosures per year

  1. 2021: 1
  2. 2022: 0
  3. 2023: 1
  4. 2024: 0
  5. 2025: 0
  6. 2026: 0
  1. MooTools Regular Expression Denial of Service this entry
    High · 7.5 CVE-2021-32821 <= 1.5.2 no fix
  2. Medium · 5.4 CVE-2021-23432 <= 1.5.2 no fix

Know which vulnerabilities affect your application

With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.

Connect your application
DockRay newsletter

Application security in your inbox

Important vulnerabilities, actionable guidance and practical advice for your applications. Choose your technologies and follow what matters to your project.

  • A daily digest of new vulnerabilities, critical ones included.
  • Notifications about important updates.
  • Practical advice on application security and monitoring.

Leave empty to receive updates for every technology.

Free to subscribe. Unsubscribe with one click in any email.