CVE-2026-90771

joi before 17.13.8 and 18.2.9 Prototype Pollution via messages

Published Sep 13, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
Description
joi before versions 17.13.8 and 18.2.9 contains a prototype pollution vulnerability in the messages compilation function that accepts __proto__ as an error code. Attackers can supply __proto__ keys in custom messages to replace the returned object's prototype, breaking downstream code relying on Object.prototype methods.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-wr44-6hxh-3jwq joi messages compilation allows prototype replacement through __proto__ error codes
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Hapijs
Hapijs joi
Vendors & Products Hapijs
Hapijs joi
Type Values Removed Values Added
Description joi before versions 17.13.8 and 18.2.9 contains a prototype pollution vulnerability in the messages compilation function that accepts __proto__ as an error code. Attackers can supply __proto__ keys in custom messages to replace the returned object's prototype, breaking downstream code relying on Object.prototype methods.
Title joi before 17.13.8 and 18.2.9 Prototype Pollution via messages
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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 24, 2026, 2:21 PM
Reserved
Sep 13, 2026, 10:14 AM
Status
Awaiting Analysis
Published
Sep 13, 2026, 11:17 AM
Modified
Sep 24, 2026, 8:44 PM
Severity
Moderate
Public date
Sep 13, 2026, 10:45 AM