Vulnerability-Lookup

GHSA-QXCH-WHHJ-8956

Vulnerability from github – Published: 2026-05-18 17:35 – Updated: 2026-05-18 17:35

Summary

multiparty: Denial of Service via Prototype Pollution leads to Uncaught Exception

Details

Impact

multiparty@4.2.3 and lower versions are vulnerable to denial of service via uncaught exception. By sending a multipart/form-data request with a field name that collides with an inherited Object.prototype property (e.g., __proto__, constructor, toString), the parser invokes .push() on the inherited prototype value rather than an array, throwing a TypeError that propagates as an uncaught exception and crashes the process. Any service accepting multipart uploads via multiparty is affected.

Patches

Users should upgrade to multiparty@4.3.0 or higher.

Workarounds

None.

Severity

7.5 (High)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.2.3"
      },
      "package": {
        "ecosystem": "npm",
        "name": "multiparty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-8161"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321",
      "CWE-248"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-18T17:35:01Z",
    "nvd_published_at": "2026-05-12T10:16:48Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nmultiparty@4.2.3 and lower versions are vulnerable to denial of service via uncaught exception. By sending a `multipart/form-data` request with a field name that collides with an inherited `Object.prototype` property (e.g., `__proto__`, `constructor`, `toString`), the parser invokes `.push()` on the inherited prototype value rather than an array, throwing a `TypeError` that propagates as an uncaught exception and crashes the process. Any service accepting multipart uploads via multiparty is affected.\n\n### Patches\n\nUsers should upgrade to multiparty@4.3.0 or higher.\n\n### Workarounds\n\nNone.",
  "id": "GHSA-qxch-whhj-8956",
  "modified": "2026-05-18T17:35:01Z",
  "published": "2026-05-18T17:35:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pillarjs/multiparty/security/advisories/GHSA-qxch-whhj-8956"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-8161"
    },
    {
      "type": "WEB",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pillarjs/multiparty"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pillarjs/multiparty/releases/tag/v4.3.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "multiparty: Denial of Service via Prototype Pollution leads to Uncaught Exception"
}

CVE-2026-8161 (GCVE-0-2026-8161)

Vulnerability from cvelistv5 – Published: 2026-05-12 08:50 – Updated: 2026-05-12 12:32

Title

multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception

Summary

multiparty@4.2.3 and lower versions are vulnerable to denial of service via uncaught exception. By sending a multipart/form-data request with a field name that collides with an inherited Object.prototype property such as __proto__, constructor, or toString, the parser invokes .push() on the inherited prototype value rather than an array, throwing a TypeError that propagates as an uncaught exception and crashes the process. Impact: any service accepting multipart uploads via multiparty is affected. Workarounds: none. Upgrade to multiparty@4.3.0 or higher.

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-12 12:31 UTC

CWE

CWE-248 - Uncaught Exception
CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Assigner

openjs redhat root

References

2 references

URL	Tags
https://github.com/pillarjs/multiparty/security/a…
https://cna.openjsf.org/security-advisories.html

Impacted products

1 product

Vendor	Product	Version
multiparty	multiparty	Affected: 0 , ≤ 4.2.3 (semver) Unaffected: 4.3.0 (semver)

Credits

Ser0n-ath Sebastian Beltran kq5y Byambadalai Sumiya Blake Embrey Ulises Gascón

Show details on NVD website

JSON

To clipboard

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        "metrics": [
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                "id": "CVE-2026-8161",
                "options": [
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                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-12T12:31:39.867190Z",
                "version": "2.0.3"
              },
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        "providerMetadata": {
          "dateUpdated": "2026-05-12T12:32:10.127Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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        }
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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.

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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