Prototype Pollution

published 2022-05-01 4 y ago modified 2026-06-17 4 mo ago also GHSA-p3pg-64pv-v7jg , EUVD-2022-4668

cvss: 7.7; 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 69%
public exploits: 0; none known

All versions of package jsgui-lang-essentials are vulnerable to Prototype Pollution due to allowing all Object attributes to be altered, including their magical attributes such as proto, constructor and prototype.

Exploit prediction

1.24% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

snyk.io https://snyk.io/vuln/SNYK-JS-JSGUILANGESSENTIALS-2316897 referenced PoC, tagged "exploit" by a source, unverified
github.com https://github.com/metabench/jsgui-lang-essentials/issues/1 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.7	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H/E:P
CNA	3.1	7.7	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H
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	7.7	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	jsgui-lang-essentials	<=0.4.3	no fix listed

Affected products

n/a jsgui-lang-essentials

Classification

Weakness

CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

snyk.io /vuln/SNYK-JS-JSGUILANGESSENTIALS-2316897
web, exploit, third-party-advisory
github.com /metabench/jsgui-lang-essentials/issues/1
web, exploit, issue-tracking, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2022-25301
advisory
github.com /metabench/jsgui-lang-essentials
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