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Fencer Vulns
low 3.7

CVE-2026-84368 json

joi: Prototype pollution via a `__proto__` language key in custom messages

published 2026-09-01 2 mo ago modified 2026-11-05 4 d ago also CVE-2026-122131 , GHSA-6w3j-5fw6-r9vr , EUVD-2026-69649

cvss
3.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits
0
none known

Summary

joi is a schema description language and data validator for JavaScript. From 16.0.0 until 17.13.6 and 18.2.5, the @hapi/joi package through 17.1.1 and the successor joi package contain prototype pollution in lib/messages.js, where exports.compile() and exports.merge() reuse inherited objects for attacker-controlled language keys supplied through messages(), message(), prefs({ messages }), Joi.extend({ messages }), or rule({ message }). A language key named __proto__ writes properties onto Object.prototype, and constructor writes to the Object function's static properties. A consuming application that gates on the presence of an inherited property can take the wrong branch for every inspected object. The flaw is not reachable from data that joi validates and requires an application to feed untrusted input directly into schema-construction configuration. This issue is fixed in joi versions 17.13.6 and 18.2.5; no fixed @hapi/joi version is available.

Patch / fix

  • npm joi 17.13.6, 18.2.5

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-2026-84368 updated cvss 3.7

joi: @hapi/joi: joi: Prototype pollution via untrusted input in schema configuration

  • Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9 Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-ui-rhel8 Red Hat Build of Podman Desktop rh-podman-desktop.git Red Hat Data Grid 8 redhat-datagrid-maven-repository.zip Red Hat Enterprise Linux 8 pcs, grafana, pcs-snmp, grafana-pcp, grafana-loki, grafana-mssql, +12 more Red Hat Enterprise Linux 9 grafana, grafana-selinux, grafana 12.4.3-2.el10
    +1 more products
    Red Hat Enterprise Linux 10 grafana 12.4.3-2.el10
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Fuse 7 joi 15.1.1
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-dashboard-rhel9, rhoai/odh-mod-arch-maas-rhel9, rhoai/odh-mod-arch-automl-rhel9, rhoai/odh-mod-arch-gen-ai-rhel9, rhoai/odh-mod-arch-mlflow-rhel9, rhoai/odh-mod-arch-autorag-rhel9, +2 more Red Hat OpenShift Container Platform 4 openshift4/ose-agent-installer-ui-rhel9 Red Hat OpenShift Container Platform 5 openshift5/ose-agent-installer-ui-rhel9 Red Hat OpenShift Dev Spaces devspaces/dashboard-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images grafana12.4 12.4.9-0.4.hum1, grafana13.1 13.1.3-0.3.hum1, grafana13.2 13.2.0-0.1.2.hum1
    not affected: vulnerable code not present

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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
GitHub 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
npm joi
>=17.2.0, <17.13.6
>=18.0.0, <18.2.5
17.13.6
18.2.5
npm @hapi/joi
>=16.0.0, <=17.1.1
 no fix listed

Affected products

  • hapijs joi

Classification

Weakness
  • CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

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.