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Fencer Vulns
low 3.7

CVE-2026-84367 json

joi: object().rename() with a template target can set the validated object's prototype

published 2026-09-01 2 mo ago modified 2026-09-09 1 mo ago also GHSA-gg4h-3hg2-grpc , EUVD-2026-69648

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 17.13.5 and 18.2.4, joi's lib/types/keys.js internals.rename() implementation used by object().rename() permits a schema that renames keys with a regular-expression source and a Joi.expression() or Joi.x() target that interpolates the pattern's own match data, combined with { multiple: true }, to derive a target from an attacker-controlled input key. An attacker can send x-__proto__ with an object value, causing the target to render as __proto__ and set the prototype of the object returned by validate() instead of creating an own key. The global Object.prototype is not modified, so the effect is confined to the object returned by that validation call. Static-string targets and schemas using the default { multiple: false } are not affected. This issue is fixed in versions 17.13.5 and 18.2.4.

Patch / fix

  • npm joi 17.13.5, 18.2.4

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-2026-84367 updated cvss 3.7

joi: joi: Prototype pollution via dynamic key renaming

  • Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9 Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-ui-rhel8 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: no fix available “Fix deferred”
  • Red Hat Build of Podman Desktop rh-podman-desktop.git
    under investigation
  • Red Hat Build of Podman Desktop rh-podman-desktop 3c6fc75a2a6cf5bb9b8a667fddcbbf428132badc Red Hat Data Grid 8 redhat-datagrid-maven-repository.zip 8.6.1.CR1 Red Hat Enterprise Linux 8 grafana, grafana-pcp, grafana-loki, grafana-mssql, grafana-mysql, grafana-selinux, +10 more Red Hat Enterprise Linux 9 grafana, grafana-selinux, grafana 12.4.3-2.el10 Red Hat Enterprise Linux 10 grafana 12.4.3-2.el10 Red Hat Hardened Images grafana13.1 13.1.6-0.3.hum1, grafana13.2 13.2.1-0.7.hum1, grafana12.4 12.4.10-0.8.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
>=16.0.0, <17.13.5
>=18.0.0, <18.2.4
17.13.5
18.2.4

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.