CVE-2021-44906
CVE-2021-44906 is a critical-severity vulnerability in Substack Minimist with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1321.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v2: 7.5
- EPSS exploit prediction: 5% (91st percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-1321
- Affected product: Substack Minimist
- Published:
- Last modified:
Description
Minimist <=1.2.5 is vulnerable to Prototype Pollution via file index.js, function setKey() (lines 69-95).
Frequently asked questions
- What is CVE-2021-44906?
- Minimist <=1.2.5 is vulnerable to Prototype Pollution via file index.js, function setKey() (lines 69-95).
- How severe is CVE-2021-44906?
- CVE-2021-44906 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-44906 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-44906?
- CVE-2021-44906 affects Substack Minimist. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-44906?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2021-44906 published?
- CVE-2021-44906 was published on 2022-03-17 and last updated on 2026-06-17.
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
Affected products (1)
- cpe:2.3:a:substack:minimist:*:*:*:*:*:node.js:*:*
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- CVE-2020-7598 — Medium (CVSS 5.6): minimist before 1.2.2 could be tricked into adding or modifying properties of Object.prototype using a "constructor" or…
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