Vulnerability-Lookup

CVE-2026-92781 (GCVE-0-2026-92781)

Vulnerability from cvelistv5 – Published: 2026-09-16 20:32 – Updated: 2026-09-16 20:32

Title

Builder.io Gen2 SDKs through 5.2.11 Prototype Pollution via builder.userAttributes

Summary

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

5.3 (Medium)


                        
                          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

6.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

CWE

CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Assigner

VulnCheck mitre root

References

5 references

URL	Tags
https://github.com/BuilderIO/builder/issues/4824	issue-tracking
https://github.com/BuilderIO/builder	product
https://github.com/BuilderIO/builder/blob/main/pa…	technical-description
https://github.com/BuilderIO/builder/blob/main/pa…	technical-description
https://www.vulncheck.com/advisories/builder-io-g…	third-party-advisory

Impacted products

7 products

Vendor	Product	Version	CPE status
BuilderIO	@builder.io/sdk-react	Affected: 0 , ≤ 5.2.11 (semver)	guessed
BuilderIO	@builder.io/sdk-vue	Affected: 0 , ≤ 5.2.11 (semver)	guessed
BuilderIO	@builder.io/sdk-svelte	Affected: 0 , ≤ 5.2.11 (semver)	guessed
BuilderIO	@builder.io/sdk-solid	Affected: 0 , ≤ 5.2.11 (semver)	guessed
BuilderIO	@builder.io/sdk-qwik	Affected: 0 , ≤ 0.25.13 (semver)	guessed
BuilderIO	@builder.io/sdk-angular	Affected: 0 , ≤ 0.25.13 (semver)	guessed
BuilderIO	@builder.io/sdk-react-nextjs	Affected: 0 , ≤ 0.25.13 (semver)	guessed

Date Public

2026-08-25 00:00

Credits

George Chen

Show details on NVD website

JSON

To clipboard

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}

FKIE_CVE-2026-92781

Vulnerability from fkie_nvd - Published: 2026-09-16 21:17 - Updated: 2026-09-16 21:17

Severity

6.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

Summary

References

	URL	Tags
	disclosure@vulncheck.com	https://github.com/BuilderIO/builder
	disclosure@vulncheck.com	https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/functions/get-content/generate-content-url.ts
	disclosure@vulncheck.com	https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/helpers/flatten.ts#L60-L76
	disclosure@vulncheck.com	https://github.com/BuilderIO/builder/issues/4824
	disclosure@vulncheck.com	https://www.vulncheck.com/advisories/builder-io-gen2-sdks-through-5.2.11-prototype-pollution-via-builder-userattributes

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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  ],
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          "userInteraction": "PASSIVE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "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",
          "version": "4.0",
          "vulnAvailabilityImpact": "LOW",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "LOW",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-16T21:17:27.130",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/BuilderIO/builder"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/functions/get-content/generate-content-url.ts"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/helpers/flatten.ts#L60-L76"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/BuilderIO/builder/issues/4824"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://www.vulncheck.com/advisories/builder-io-gen2-sdks-through-5.2.11-prototype-pollution-via-builder-userattributes"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1321"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Primary"
    }
  ]
}

GHSA-MGR8-FXXV-82MJ

Vulnerability from github – Published: 2026-09-16 21:32 – Updated: 2026-09-16 21:32

Details

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

6.3 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

5.3 (Medium)


                  
                    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

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2026-92781"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T21:17:27Z",
    "severity": "MODERATE"
  },
  "details": "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\u0027s browser when the SDK processes the malicious URL.",
  "id": "GHSA-mgr8-fxxv-82mj",
  "modified": "2026-09-16T21:32:54Z",
  "published": "2026-09-16T21:32:54Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-92781"
    },
    {
      "type": "WEB",
      "url": "https://github.com/BuilderIO/builder/issues/4824"
    },
    {
      "type": "WEB",
      "url": "https://github.com/BuilderIO/builder"
    },
    {
      "type": "WEB",
      "url": "https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/functions/get-content/generate-content-url.ts"
    },
    {
      "type": "WEB",
      "url": "https://github.com/BuilderIO/builder/blob/main/packages/sdks/src/helpers/flatten.ts#L60-L76"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/builder-io-gen2-sdks-through-5.2.11-prototype-pollution-via-builder-userattributes"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-92781 (GCVE-0-2026-92781)

FKIE_CVE-2026-92781

GHSA-MGR8-FXXV-82MJ

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