CVSS 4.0
5.3 mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:NCVE-2026-92781
Medium (5.3). EPSS 0.4% chance of exploitation in the next 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.
Severity
CVSS 3.1
6.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 29% of CVEs (scores of 2026-10-31)
- CWE
- CWE-1321
- Published
- Modified
- Record from
- the NVD, synced
References
- https://github.com/BuilderIO/builder
- https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/functions/get-content/generate-content-url.ts
- https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/helpers/flatten.ts#L60-L76
- https://github.com/BuilderIO/builder/issues/4824
- https://www.vulncheck.com/advisories/builder-io-gen2-sdks-through-5.2.11-prototype-pollution-via-builder-userattributes