Prototype Pollution

published 2021-11-03 5 y ago modified 2026-09-10 1 mo ago also GHSA-282f-qqgm-c34q , EUVD-2021-2277

cvss: 5.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 2.8%; EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits: 0; none known

This affects the package jsonpointer before 5.0.0. A type confusion vulnerability can lead to a bypass of a previous Prototype Pollution fix when the pointer components are arrays.

Patch / fix

fixed in 3 links 4

npm jsonpointer 5.0.0
npm org.webjars.npm:json-pointer 5.0.0
n/a jsonpointer 5.0.0

github.com/janl/node-jsonpointer@a0345f3 commit
github.com/janl/node-jsonpointer#51 pull request
snyk.io/vuln/SNYK-JS-JSONPOINTER-1577288 advisory
snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1910273 advisory

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-2021-23807 updated 2026-07-03 cvss 7.3

nodejs-jsonpointer: type confusion vulnerability can lead to a bypass of a previous prototype pollution fix when the pointer components are arrays

Red Hat OpenShift Container Platform 3.11 kibana
affected: no fix planned “Out of support scope”
Red Hat OpenShift Container Platform 4 openshift4/ose-metering-hadoop Red Hat Quay 3 quay/quay-rhel8
affected: no fix planned “Will not fix”

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

2.75% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

snyk.io https://snyk.io/vuln/SNYK-JS-JSONPOINTER-1577288 referenced PoC, tagged "exploit" by a source, unverified
snyk.io https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1910273 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/RL:O/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
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P
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	jsonpointer	<5.0.0	5.0.0
npm	org.webjars.npm:json-pointer	<5.0.0	5.0.0

Affected products

n/a jsonpointer

Classification

Weakness

CWE-843 Access of Resource Using Incompatible Type
CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

github.com /janl/node-jsonpointer/pull/51
web, patch, third-party-advisory
github.com /janl/node-jsonpointer/commit/a0345f3550cd9c4d89f33b126390202b89510ad4
web, patch, third-party-advisory
snyk.io /vuln/SNYK-JS-JSONPOINTER-1577288
web, exploit, mitigation, patch, third-party-advisory, vdb-entry
snyk.io /vuln/SNYK-JAVA-ORGWEBJARSNPM-1910273
web, exploit, mitigation, patch, third-party-advisory, vdb-entry
nvd.nist.gov /vuln/detail/CVE-2021-23807
advisory
github.com /janl/node-jsonpointer
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