CVE-2026-122131

    Dashboard / Vulnerabilities / CVE-2026-122131

    CVE-2026-122131

    Published: 4 Nov 2026Last Modified: 7 Nov 2026

    Summary: Joi 17.13.6 before 17.13.9 and 18.2.5 before 18.3.1 Prototype Replacement via __proto__ Language Key

    Details: 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.

    References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/122xxx/CVE-2026-122131.json, https://github.com/hapijs/joi/security/advisories/GHSA-6w3j-5fw6-r9vr, https://nvd.nist.gov/vuln/detail/CVE-2026-122131, 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, https://github.com/hapijs/joi/commit/76f5771e1afe527cfda24be0e1a920ffa54888d6, https://github.com/hapijs/joi/commit/dae9467cec27e787bfdea8b276595177d52d28ec, https://github.com/hapijs/joi/pull/3164, https://github.com/hapijs/joi, https://github.com/hapijs/joi/blob/v18.3.0/lib/messages.js#L64-L67

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 850be1ee24be8d548bb09359bdb0cf9fe41635ff
    Fixed -5af45306226782035951fdc49f10fab5ebe021a2

    Affected versions

    v17.13.8
    v17.13.7
    v17.13.6

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2026-122131 | CVE-DB