CVE-2026-92781 MEDIUM

CVE-2026-92781: Builder.io Gen2 SDKs through 5.2.11 Prototype Pollution via builder.userAttributes

Vendor Builderio
Product @builder.io/sdk-react
Weakness CWE-1321
Published September 16, 2026
Last update September 21, 2026

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction —
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

September 16, 2026 CVE published
September 21, 2026 Record updated