{"id":"CVE-2026-90771","state":"PUBLISHED","title":"joi before 17.13.8 and 18.2.9 Prototype Pollution via messages","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.","publishedAt":"2026-09-13T10:45:42.498Z","updatedAt":"2026-09-24T14:21:52.339Z","severity":{"score":6.3,"label":"Medium","version":"4.0","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","source":"VulnCheck"},"assigner":"VulnCheck","products":["hapijs joi"],"affected":[{"vendor":"hapijs","product":"joi","packageURL":"pkg:npm/joi","defaultStatus":"unaffected","versions":[{"version":"16.0.0","status":"affected","lessThan":"17.13.8","versionType":"semver"},{"version":"18.0.0","status":"affected","lessThan":"18.2.9","versionType":"semver"}]}],"references":["https://github.com/hapijs/joi/issues/3150","https://github.com/hapijs/joi","https://github.com/hapijs/joi/blob/v18.2.8/lib/messages.js","https://github.com/hapijs/joi/commit/5b8333c9177e08b4ef4ed02903c2d657084e7afb","https://www.vulncheck.com/advisories/joi-before-17.13.8-and-18.2.9-prototype-pollution-via-messages"],"weaknesses":["CWE-1321"],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90771.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90771","state":"PUBLISHED","datePublished":"2026-09-13T10:45:42.498Z","dateUpdated":"2026-09-24T14:21:52.339Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-13T10:14:57.680Z"},"containers":{"cna":{"title":"joi before 17.13.8 and 18.2.9 Prototype Pollution via messages","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"hapijs","product":"joi","packageURL":"pkg:npm/joi","defaultStatus":"unaffected","versions":[{"version":"16.0.0","status":"affected","lessThan":"17.13.8","versionType":"semver"},{"version":"18.0.0","status":"affected","lessThan":"18.2.9","versionType":"semver"}]}],"references":[{"url":"https://github.com/hapijs/joi/issues/3150","tags":["issue-tracking"],"name":"GitHub Issue #3150"},{"url":"https://github.com/hapijs/joi","tags":["product"]},{"url":"https://github.com/hapijs/joi/blob/v18.2.8/lib/messages.js","tags":["technical-description"]},{"url":"https://github.com/hapijs/joi/commit/5b8333c9177e08b4ef4ed02903c2d657084e7afb","tags":["patch"]},{"url":"https://www.vulncheck.com/advisories/joi-before-17.13.8-and-18.2.9-prototype-pollution-via-messages","name":"VulnCheck Advisory: joi before 17.13.8 and 18.2.9 Prototype Pollution via messages","tags":["third-party-advisory"]}],"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1321","lang":"en","description":"Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-09-24T14:21:52.339Z"},"datePublic":"2026-09-09T00:00:00.000Z","credits":[{"lang":"en","value":"George Chen","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/hapijs/joi/issues/3150","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-16T14:02:28.580545Z","id":"CVE-2026-90771","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-16T14:03:23.974Z"}}]}}}