What’s Vulnerable › Vulnerabilities

CVE-2020-28501: Regular Expression Denial of Service (ReDoS)

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-03-22 · updated 2026-06-17

Description

This affects the package es6-crawler-detect before 3.1.3. No limitation of user agent string length supplied to regex operators.

Affected products

• Crawlerdetect Project Crawlerdetect: before 3.1.3 — fixed in 3.1.3

How to fix

Upgrade to a fixed version: Crawlerdetect Project Crawlerdetect 3.1.3. Check the vendor advisory for mitigations.

References

• https://github.com/JefferyHus/es6-crawler-detect/pull/27
• https://snyk.io/vuln/SNYK-JS-ES6CRAWLERDETECT-1051529
• https://github.com/JefferyHus/es6-crawler-detect/pull/27
• https://snyk.io/vuln/SNYK-JS-ES6CRAWLERDETECT-1051529

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