{"cve":"CVE-2026-84368","nvd":{"published":"2026-09-01T21:18:47.887","modified":"2026-09-09T21:09:13.080","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","score":3.7},"cwes":["CWE-1321"],"references":["https://github.com/hapijs/joi/commit/8d0b808f3e874d28f9078f61b7742290989afb36","https://github.com/hapijs/joi/commit/90d07571923c90e3432a328fc041d1cda03d30fa","https://github.com/hapijs/joi/pull/3138","https://github.com/hapijs/joi/pull/3139","https://github.com/hapijs/joi/security/advisories/GHSA-6w3j-5fw6-r9vr"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:50.842544443+00:00"},"epss":{"cve":"CVE-2026-84368","score":0.00389,"percentile":0.33034,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-6w3j-5fw6-r9vr","url":"https://osv.dev/vulnerability/GHSA-6w3j-5fw6-r9vr","summary":"joi: Prototype pollution via a `__proto__` language key in custom messages","modified":"2026-09-08T21:15:03.964614980Z","packages":[{"ecosystem":"npm","name":"joi","purl":"pkg:npm/joi","ranges":[">=17.2.0 <17.13.6"],"fixed":["17.13.6"]},{"ecosystem":"npm","name":"@hapi/joi","purl":"pkg:npm/%40hapi/joi","ranges":[">=16.0.0 <=17.1.1"],"fixed":[]},{"ecosystem":"npm","name":"joi","purl":"pkg:npm/joi","ranges":[">=18.0.0 <18.2.5"],"fixed":["18.2.5"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}