Prototype Pollution in Substack Minimist

CVE-2021-44906

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

Vulnerability class: Prototype Pollution

EPSS: 0.046 (90.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-44906?
CVE-2021-44906 is a critical-severity vulnerability in Substack Minimist, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 9.8/10. Published 2022-03-17.
How severe is CVE-2021-44906?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-44906 known to be exploited?
13 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.