CVE-2026-90771

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.

CVSS v3 3.7 LOW

3.7^/10

CVSS v3 : LOW

Vector :

Exploitability : 2.2 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
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://github.com/hapijs/joi/issues/3150
https://www.vulncheck.com/advisories/joi-before-17.13.8-and-18.2.9-prototype-pollution-via-messages
https://github.com/hapijs/joi/issues/3150

Configurations

No configuration.

History

16 Sep 2026, 15:18

Type	Values Removed	Values Added
References	~~() https://github.com/hapijs/joi/issues/3150 -~~	() https://github.com/hapijs/joi/issues/3150 -

Information

Published : 2026-09-13 11:17

Updated : 2026-09-16 15:18

NVD link : CVE-2026-90771

Mitre link : CVE-2026-90771

CVE.ORG link : CVE-2026-90771

JSON object : View

Products Affected

No product.

CWE

CWE-1321

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

{"id": "CVE-2026-90771", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-90771", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-16T14:02:28.580545Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.7, "attackVector": "NETWORK", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 2.2}], "cvssMetricV40": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 6.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "LOW", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "disclosure@vulncheck.com", "affectedData": [{"vendor": "hapijs", "product": "joi", "versions": [{"status": "affected", "version": "16.0.0", "lessThan": "17.13.8", "versionType": "semver"}, {"status": "affected", "version": "18.0.0", "lessThan": "18.2.9", "versionType": "semver"}], "packageURL": "pkg:npm/joi", "defaultStatus": "unaffected"}]}], "published": "2026-09-13T11:17:01.613", "references": [{"url": "https://github.com/hapijs/joi", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/hapijs/joi/blob/v18.2.8/lib/messages.js", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/hapijs/joi/commit/5b8333c9177e08b4ef4ed02903c2d657084e7afb", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/hapijs/joi/issues/3150", "source": "disclosure@vulncheck.com"}, {"url": "https://www.vulncheck.com/advisories/joi-before-17.13.8-and-18.2.9-prototype-pollution-via-messages", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/hapijs/joi/issues/3150", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "description": [{"lang": "en", "value": "CWE-1321"}]}], "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."}], "lastModified": "2026-09-16T15:18:42.280", "sourceIdentifier": "disclosure@vulncheck.com"}