CVE-2026-92781
CVE-2026-92781
Builder.io Gen2 SDKs through versions 5.2.11 and 0.25.13 contain a prototype pollution vulnerability in the unflatten helper that processes builder.userAttributes query parameters without prototype guards. Attackers can craft preview links with __proto__ or prototype segments to pollute Object.prototype in a visitor's browser when the SDK processes the malicious URL.
Vulnerability class: Prototype Pollution
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L.
Weakness classification (CWE)
References
- disclosure@vulncheck.com (issue-tracking)
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-92781?
- CVE-2026-92781 is a medium-severity vulnerability, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 6.3/10. Published 2026-09-16.
- How severe is CVE-2026-92781?
- Medium severity. CVSS v3 base score is 6.3 out of 10.