What’s Vulnerable › Vulnerabilities

CVE-2021-33502

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-05-24 · updated 2026-06-17
• Weakness: CWE-1333

Description

The normalize-url package before 4.5.1, 5.x before 5.3.1, and 6.x before 6.0.1 for Node.js has a ReDoS (regular expression denial of service) issue because it has exponential performance for data: URLs.

Affected products

• Normalize-Url Project Normalize-Url: from 4.3.0 before 4.5.1; from 5.0.0 before 5.3.1; 6.0.0 — fixed in 4.5.1, 5.3.1

How to fix

Upgrade to a fixed version: Normalize-Url Project Normalize-Url 4.5.1, 5.3.1. Check the vendor advisory for mitigations.

References

• https://github.com/sindresorhus/normalize-url/releases/tag/v6.0.1
• https://security.netapp.com/advisory/ntap-20210706-0001/
• https://github.com/sindresorhus/normalize-url/releases/tag/v6.0.1
• https://security.netapp.com/advisory/ntap-20210706-0001/

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