Medium 6.3Published Sep 16, 2026

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

Updated under an hour ago (Oct 28, 2026, 1:30 AM ET)

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It affects BuilderIO @builder.io/sdk-react and 6 other products. Add what you run to find out whether that includes you.

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Every CVE for BuilderIO @builder.io/sdk-react

Exploited in the last 30 days

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.

CVSS: 6.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
Weakness (CWE): CWE-1321
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Sep 21, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

BuilderIO @builder.io/sdk-react builderio:builder.io_sdk_react (from the name)	through 5.2.11	CNA record
BuilderIO @builder.io/sdk-vue builderio:builder.io_sdk_vue (from the name)	through 5.2.11	CNA record
BuilderIO @builder.io/sdk-svelte builderio:builder.io_sdk_svelte (from the name)	through 5.2.11	CNA record
BuilderIO @builder.io/sdk-solid builderio:builder.io_sdk_solid (from the name)	through 5.2.11	CNA record
BuilderIO @builder.io/sdk-qwik builderio:builder.io_sdk_qwik (from the name)	through 0.25.13	CNA record
BuilderIO @builder.io/sdk-angular builderio:builder.io_sdk_angular (from the name)	through 0.25.13	CNA record
BuilderIO @builder.io/sdk-react-nextjs builderio:builder.io_sdk_react_nextjs (from the name)	through 0.25.13	CNA record

References

References

https://github.com/BuilderIO/builder/issues/4824	issue-tracking
https://github.com/BuilderIO/builder	product
https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/functions/get-content/generate-content-url.ts	technical-description
https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/helpers/flatten.ts#L60-L76	technical-description
https://www.vulncheck.com/advisories/builder-io-gen2-sdks-through-5.2.11-prototype-pollution-via-builder-userattributes	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.