Prototype Pollution

published 2021-10-11 5 y ago modified 2026-07-08 4 mo ago also GHSA-2w3f-9w3q-qw77 , EUVD-2021-2141

cvss: 6.5; 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

All versions of package config-handler are vulnerable to Prototype Pollution when loading config files.

Exploit prediction

1.19% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

snyk.io https://snyk.io/vuln/SNYK-JS-CONFIGHANDLER-1564947 referenced PoC, tagged "exploit" by a source, unverified
github.com https://github.com/jarradseers/config-handler/issues/1 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P
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	config-handler	<=2.0.3	no fix listed

Affected products

n/a config-handler

Classification

Weakness

CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
CWE-913 Improper Control of Dynamically-Managed Code Resources

References

snyk.io /vuln/SNYK-JS-CONFIGHANDLER-1564947
web, exploit, issue-tracking, mitigation, third-party-advisory
github.com /jarradseers/config-handler/issues/1
web, exploit, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2021-23448
advisory
github.com /jarradseers/config-handler
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