{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-122131","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-11-04T18:13:10.837Z","datePublished":"2026-11-04T20:36:51.069Z","dateUpdated":"2026-11-05T19:40:15.094Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-11-04T20:36:51.069Z"},"datePublic":"2026-10-28T00:00:00.000Z","title":"Joi 17.13.6 before 17.13.9 and 18.2.5 before 18.3.1 Prototype Replacement via __proto__ Language Key","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')","cweId":"CWE-1321","type":"CWE"}]}],"affected":[{"vendor":"hapijs","product":"joi","defaultStatus":"unaffected","packageURL":"pkg:npm/joi","versions":[{"version":"17.13.6","status":"affected","lessThan":"17.13.9","versionType":"semver"},{"version":"18.2.5","status":"affected","lessThan":"18.3.1","versionType":"semver"}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.3,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":3.7,"baseSeverity":"LOW"}}],"references":[{"url":"https://github.com/hapijs/joi/commit/76f5771e1afe527cfda24be0e1a920ffa54888d6","tags":["patch"],"name":"Patch Commit"},{"url":"https://github.com/hapijs/joi","tags":["product"]},{"url":"https://github.com/hapijs/joi/commit/dae9467cec27e787bfdea8b276595177d52d28ec","tags":["patch"]},{"url":"https://github.com/hapijs/joi/pull/3164","tags":["patch","issue-tracking"]},{"url":"https://github.com/hapijs/joi/security/advisories/GHSA-6w3j-5fw6-r9vr","tags":["related","vendor-advisory"],"name":"GitHub Security Advisory (GHSA-6w3j-5fw6-r9vr)"},{"url":"https://github.com/hapijs/joi/blob/v18.3.0/lib/messages.js#L64-L67","tags":["technical-description"]},{"name":"VulnCheck Advisory: Joi 17.13.6 before 17.13.9 and 18.2.5 before 18.3.1 Prototype Replacement via __proto__ Language Key","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/joi-17.13.6-before-17.13.9-and-18.2.5-before-18.3.1-prototype-replacement-via-proto-language-key"}],"credits":[{"lang":"en","value":"Zachariah Mithani (AploSec)","type":"finder"},{"lang":"en","value":"Marsup","type":"remediation developer"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-11-05T19:39:47.724527Z","id":"CVE-2026-122131","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-11-05T19:40:15.094Z"}}]}}