Vulnerability-Lookup

GHSA-72GW-MP4G-V24J

Vulnerability from github – Published: 2026-06-17 18:12 – Updated: 2026-06-17 18:12

Summary

Multer vulnerable to Denial of Service via deeply nested field names

Details

Impact

Multer is vulnerable to a Denial of Service (DoS) via deeply nested field names in multipart form data. The append-field dependency parses bracket notation in field names (e.g., a[b][c]) with no limit on nesting depth, allowing an attacker to force allocation of deeply nested object structures that consume CPU and memory. A single HTTP request with a crafted multipart body is sufficient to exploit this.

Patches

Users should upgrade to 2.2.0 and configure limits.fieldNestingDepth to the minimum depth their application requires.

Workarounds

Set limits.fields to a reasonable value to reduce the number of fields an attacker can send per request. This does not fully mitigate the issue but limits the impact.

Severity

7.5 (High)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "multer"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0"
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              "fixed": "2.2.0"
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        }
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    }
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  "aliases": [
    "CVE-2026-5079"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-17T18:12:27Z",
    "nvd_published_at": "2026-06-15T14:16:37Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nMulter is vulnerable to a Denial of Service (DoS) via deeply nested field names in multipart form data. The `append-field` dependency parses bracket notation in field names (e.g., `a[b][c]`) with no limit on nesting depth, allowing an attacker to force allocation of deeply nested object structures that consume CPU and memory. A single HTTP request with a crafted multipart body is sufficient to exploit this.\n\n### Patches\n\nUsers should upgrade to `2.2.0` and configure `limits.fieldNestingDepth` to the minimum depth their application requires.\n\n### Workarounds\n\nSet `limits.fields` to a reasonable value to reduce the number of fields an attacker can send per request. This does not fully mitigate the issue but limits the impact.",
  "id": "GHSA-72gw-mp4g-v24j",
  "modified": "2026-06-17T18:12:27Z",
  "published": "2026-06-17T18:12:27Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/expressjs/multer/security/advisories/GHSA-72gw-mp4g-v24j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-5079"
    },
    {
      "type": "WEB",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/expressjs/multer"
    }
  ],
  "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": "Multer vulnerable to Denial of Service via deeply nested field names"
}

CVE-2026-5079 (GCVE-0-2026-5079)

Vulnerability from cvelistv5 – Published: 2026-06-15 13:56 – Updated: 2026-06-15 16:00

Title

multer vulnerable to Denial of Service via deeply nested field names

Summary

Impact: multer versions 1.0.0 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service via deeply nested field names in multipart form data. The append-field dependency parses bracket notation in field names with no limit on nesting depth, allowing an attacker to force allocation of deeply nested object structures that consume CPU and memory. A single HTTP request with a crafted multipart body is sufficient to exploit this. Patches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease) and configure the new limits.fieldNestingDepth option to the minimum depth their application requires. Workarounds: Set limits.fields to a reasonable value to reduce the number of fields an attacker can send per request. This does not fully mitigate the issue but limits the impact.

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 (v2.0.3)

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

openjs

References

2 references

URL	Tags
https://github.com/expressjs/multer/security/advi…
https://cna.openjsf.org/security-advisories.html

Impacted products

1 product

Vendor	Product	Version
multer	multer	Affected: 1.0.0 , < 2.2.0 (semver) Unaffected: 2.2.0 (semver) Affected: 3.0.0-alpha.1 , < 3.0.0-alpha.2 (semver) Unaffected: 3.0.0-alpha.2 (semver)

Credits

tndud042713 UlisesGascon

Show details on NVD website

JSON

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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.

Detection rules are retrieved from Rulezet.

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