Description
Joi 17.13.6 before 17.13.9 and 18.2.5 before 18.3.1 contains a prototype pollution vulnerability in lib/messages.js compile() and merge() that fails to reject a __proto__ language key. Attackers supplying untrusted message configuration via any().messages(), prefs, validate options or Joi.extend can replace the compiled messages prototype, altering or breaking validation error rendering and dependent logic.
Published: 2026-11-04
Score: 6.3 Medium
EPSS: < 1% Very Low
KEV: No
AI Analysis

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Remediation

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Tracking

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History

Fri, 06 Nov 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 06 Nov 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-915
References
Metrics threat_severity

None

threat_severity

Low


Wed, 04 Nov 2026 22:00:00 +0000

Type Values Removed Values Added
First Time appeared Hapijs
Hapijs joi
Vendors & Products Hapijs
Hapijs joi

Wed, 04 Nov 2026 20:45:00 +0000

Type Values Removed Values Added
Description Joi 17.13.6 before 17.13.9 and 18.2.5 before 18.3.1 contains a prototype pollution vulnerability in lib/messages.js compile() and merge() that fails to reject a __proto__ language key. Attackers supplying untrusted message configuration via any().messages(), prefs, validate options or Joi.extend can replace the compiled messages prototype, altering or breaking validation error rendering and dependent logic.
Title Joi 17.13.6 before 17.13.9 and 18.2.5 before 18.3.1 Prototype Replacement via __proto__ Language Key
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-05T19:40:15.094Z

Reserved: 2026-11-04T18:13:10.837Z

Link: CVE-2026-122131

cve-icon Vulnrichment

Updated: 2026-11-05T19:40:08.944Z

cve-icon NVD

Status : Received

Published: 2026-11-04T21:18:08.710

Modified: 2026-11-05T20:17:49.843

Link: CVE-2026-122131

cve-icon Redhat

Severity : Low

Publid Date: 2026-11-04T20:36:51Z

Links: CVE-2026-122131 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-11-06T14:00:07Z

Weaknesses
  • CWE-1321

    Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

  • CWE-915

    Improperly Controlled Modification of Dynamically-Determined Object Attributes