What’s Vulnerable › Vulnerabilities

CVE-2021-23424: Regular Expression Denial of Service (ReDoS)

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.8% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-08-18 · updated 2026-06-17

Description

This affects all versions of package ansi-html. If an attacker provides a malicious string, it will get stuck processing the input for an extremely long time.

Affected products

• ansi-html: before 0.0.8 — fixed in 0.0.8
• Npm Ansi-Html: before 0.0.8 — fixed in 0.0.8

How to fix

Upgrade to a fixed version: ansi-html 0.0.8; Npm Ansi-Html 0.0.8. Check the vendor advisory for mitigations.

References

• https://github.com/Tjatse/ansi-html/issues/19
• https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198
• https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849
• https://github.com/Tjatse/ansi-html/issues/19
• https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198
• https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849

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