Prototype Pollution

published 2022-07-25 4 y ago modified 2026-06-17 4 mo ago also GHSA-m939-vrfp-9v8p , EUVD-2022-6376

cvss: 7.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.2%; EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits: 0; none known

This affects the package js-ini before 1.3.0. If an attacker submits a malicious INI file to an application that parses it with parse , they will pollute the prototype on the application. This can be exploited further depending on the context.

Patch / fix

fixed in 2 links 1

npm js-ini 1.3.0
n/a js-ini 1.3.0

github.com/Sdju/js-ini@fa17efb commit

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-28461 updated 2025-11-21 cvss 9.8

nodejs-ini: nodejs prototype pollution

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.22% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

security.snyk.io https://security.snyk.io/vuln/SNYK-JS-JSINI-1048970 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	js-ini	<1.3.0	1.3.0

Affected products

n/a js-ini

Classification

Weakness

CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

github.com /Sdju/js-ini/commit/fa17efb7e3a7c9464508a254838d4c231784931e
web, patch, third-party-advisory
security.snyk.io /vuln/SNYK-JS-JSINI-1048970
web, exploit, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2020-28461
advisory
github.com /Sdju/js-ini
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary