CRITICAL

CVE-2021-3918

CVSS v3

9.8

CRITICAL

EPSS Score

3.8 %

exploit probability, as of 2026-10-19

CISA KEV

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

json-schemanpmall versions · fixed in 0.4.0
nodejsAlmaLinux:8all versions · fixed in 1:14.18.2-2.module_el8.5.0+254+b4526b16and 3 other packages
nodejs-nodemonAlmaLinux:8all versions · fixed in 2.0.15-1.module_el8.5.0+2618+8d46dafd
nodejs-packagingAlmaLinux:8all versions · fixed in 23-3.module_el8.4.0+2522+3bd42762
npmAlmaLinux:8all versions · fixed in 1:6.14.15-1.14.18.2.2.module_el8.5.0+254+b4526b16

Vendor advisories

CVE-2021-3918 Red Hat Product Security242 products fixed · 29 known affected
nodejs-json-schema: Prototype pollution vulnerability
migration-toolkit-virtualization/mtv-ui-rhel8 as a component of Migration Toolkit for Virtualization · servicemesh-grafana as a component of OpenShift Service Mesh 2.0 · servicemesh-grafana-prometheus as a component of OpenShift Service Mesh 2.0
RHSA-2022:7055 Red Hat Product Security6 products fixed
Red Hat Security Advisory: RHOSDT 2.6.0 operator/operand containers Security Update
RHEA-2022:5615 Red Hat Product Security30 products fixed
Red Hat Enhancement Advisory: nodejs:12 bug fix and enhancement update
RHEA-2022:5221 Red Hat Product Security30 products fixed
Red Hat Enhancement Advisory: nodejs:12 bug fix and enhancement update
RHEA-2022:5139 Red Hat Product Security30 products fixed
Red Hat Enhancement Advisory: nodejs:12 bug fix and enhancement update
RHSA-2022:4956 Red Hat Product Security204 products fixed
Red Hat Security Advisory: Red Hat Advanced Cluster Management 2.5 security updates, images, and bug fixes

7 more advisories

Full record on NVD

Description

json-schema is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Technical details

Published: 2021-11-13

Frequently asked questions

What is CVE-2021-3918?

json-schema is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Is CVE-2021-3918 actively exploited?

Active exploitation of CVE-2021-3918 has not been confirmed. Its EPSS score was 3.8% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-3918?

CVE-2021-3918 has a CVSS v3 base score of 9.8 (CRITICAL severity).

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