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.
History

Mon, 21 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Builderio
Builderio sdk-angular
Builderio sdk-qwik
Builderio sdk-react
Builderio sdk-react-nextjs
Builderio sdk-solid
Builderio sdk-svelte
Builderio sdk-vue
Vendors & Products Builderio
Builderio sdk-angular
Builderio sdk-qwik
Builderio sdk-react
Builderio sdk-react-nextjs
Builderio sdk-solid
Builderio sdk-svelte
Builderio sdk-vue

Wed, 16 Sep 2026 20:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Builder.io Gen2 SDKs through 5.2.11 Prototype Pollution via builder.userAttributes
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L'}

cvssV4_0

{'score': 5.3, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-09-16T20:32:38.923Z

Updated: 2026-09-21T15:50:13.299Z

Reserved: 2026-09-16T19:22:53.825Z

Link: CVE-2026-92781

cve-icon Vulnrichment

Updated: 2026-09-21T15:49:50.725Z

cve-icon NVD

Status : Deferred

Published: 2026-09-16T21:17:27.130

Modified: 2026-09-24T21:08:55.030

Link: CVE-2026-92781

cve-icon Redhat

No data.