Prototype Pollution

published 2022-07-25 4 y ago modified 2026-06-17 4 mo ago also GHSA-42m6-g935-5vmq , EUVD-2022-6222

cvss: 5.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits: 0; none known

All versions of package @ianwalter/merge are vulnerable to Prototype Pollution via the main (merge) function. Maintainer suggests using @generates/merger instead.

Exploit prediction

0.82% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

security.snyk.io https://security.snyk.io/vuln/SNYK-JS-IANWALTERMERGE-1311022 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.6	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RC:C
CNA	3.1	5.6	CVSS:3.1/AV:N/AC:H/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	5.6	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected packages

ecosystem	package	affected	fixed in
npm	@ianwalter/merge	<=9.0.1	no fix listed

Affected products

n/a @ianwalter/merge

Classification

Weakness

CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

security.snyk.io /vuln/SNYK-JS-IANWALTERMERGE-1311022
web, exploit, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2021-23397
advisory
github.com /ianwalter/merge
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