What’s Vulnerable › Vulnerabilities

CVE-2021-44906: Prototype Pollution in minimist

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2022-03-17 · updated 2026-10-08
• Weakness: CWE-1321

Description

Minimist <=1.2.5 is vulnerable to Prototype Pollution via file index.js, function setKey() (lines 69-95).

Affected products

• Substack Minimist: before 1.2.6 — fixed in 1.2.6
• Npm Minimist: from 1.0.0 before 1.2.6; before 0.2.4 — fixed in 1.2.6, 0.2.4

How to fix

Upgrade to a fixed version: Substack Minimist 1.2.6; Npm Minimist 1.2.6, 0.2.4. Check the vendor advisory for mitigations.

References

• https://github.com/Marynk/JavaScript-vulnerability-detection/blob/main/minimist%20PoC.zip
• https://github.com/substack/minimist/blob/master/index.js#L69
• https://github.com/substack/minimist/issues/164
• https://security.netapp.com/advisory/ntap-20240621-0006/
• https://snyk.io/vuln/SNYK-JS-MINIMIST-559764
• https://stackoverflow.com/questions/8588563/adding-custom-properties-to-a-function/20278068#20278068
• https://github.com/Marynk/JavaScript-vulnerability-detection/blob/main/minimist%20PoC.zip
• https://github.com/substack/minimist/blob/master/index.js#L69
• https://github.com/substack/minimist/issues/164
• https://security.netapp.com/advisory/ntap-20240621-0006/
• https://snyk.io/vuln/SNYK-JS-MINIMIST-559764
• https://stackoverflow.com/questions/8588563/adding-custom-properties-to-a-function/20278068#20278068

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