Affected: BuilderIO @builder.io/sdk-react, BuilderIO @builder.io/sdk-vue, BuilderIO @builder.io/sdk-svelte, BuilderIO @builder.io/sdk-solid, BuilderIO @builder.io/sdk-qwik, BuilderIO @builder.io/sdk-angular, BuilderIO @builder.io/sdk-react-nextjs

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.