{"id":"CVE-2026-92781","aliases":["EUVD-2026-81044","GHSA-mgr8-fxxv-82mj"],"status":"published","title":"Builder.io Gen2 SDKs through 5.2.11 Prototype Pollution via builder.userAttributes","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.","severity":{"version":"4.0","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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00359,"percentile":0.30065,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1321"],"published":"2026-09-16T20:32:38Z","modified":"2026-09-24T21:08:55Z","products":[{"vendor":"builderio","product":"@builder.io/sdk-angular"},{"vendor":"builderio","product":"@builder.io/sdk-qwik"},{"vendor":"builderio","product":"@builder.io/sdk-react"},{"vendor":"builderio","product":"@builder.io/sdk-react-nextjs"},{"vendor":"builderio","product":"@builder.io/sdk-solid"},{"vendor":"builderio","product":"@builder.io/sdk-svelte"},{"vendor":"builderio","product":"@builder.io/sdk-vue"}],"references":[{"url":"https://github.com/BuilderIO/builder/issues/4824","tags":["issue-tracking","exploit"]},{"url":"https://github.com/BuilderIO/builder","tags":["product"]},{"url":"https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/functions/get-content/generate-content-url.ts","tags":["technical-description"]},{"url":"https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/helpers/flatten.ts#L60-L76","tags":["technical-description"]},{"url":"https://www.vulncheck.com/advisories/builder-io-gen2-sdks-through-5.2.11-prototype-pollution-via-builder-userattributes","tags":["third-party-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92781"},{"url":"https://github.com/advisories/GHSA-mgr8-fxxv-82mj"}],"sources":{"cve":[{"id":"CVE-2026-92781","title":"Builder.io Gen2 SDKs through 5.2.11 Prototype Pollution via builder.userAttributes","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.","status":"published","published":"2026-09-16T20:32:38.923Z","modified":"2026-09-21T15:50:13.299Z","cvss":[{"version":"4.0","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","level":"medium","assessor":"cna"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T13:48:24.536396Z"}],"euvd":[{"id":"EUVD-2026-81044","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.","status":"published","published":"2026-09-16T20:32:38Z","modified":"2026-09-21T15:50:13Z","cvss":[{"version":"4.0","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","level":"medium"}],"updated_at":"2026-11-02T17:28:05.36994Z"}],"ghsa":[{"id":"GHSA-mgr8-fxxv-82mj","title":"Builder.io Gen2 SDKs through versions 5.2.11 and 0.25.13 contain a prototype pollution...","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.","status":"published","published":"2026-09-16T21:32:54Z","modified":"2026-09-16T21:32:56Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"},{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T15:12:02.762055Z"}],"nvd":[{"id":"CVE-2026-92781","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.","status":"published","published":"2026-09-16T21:17:27.13Z","modified":"2026-09-24T21:08:55.03Z","cvss":[{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T14:12:49.013904Z"}]}}