CVE-2026-5079
multer vulnerable to Denial of Service via deeply nested field names
At a glance
- Source
- NVD
- EPSS
- EPSS 0.28 % · percentile 20 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- openjs
- NVD status
- Analyzed
Description
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.
Weaknesses (CWE)
- CWE-400 — Uncontrolled Resource Consumption (DoS)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | openjs |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · ce714d77-add3-4f53-aff5-83d477b104bb (Secondary) |
Advisories
- GHSA-72gw-mp4g-v24j — Multer vulnerable to Denial of Service via deeply nested field names
European references
- ENISA EUVD · EUVD-2026-36726
- GCVE · GCVE-0-2026-5079
CERT-FR advisories
- CERTFR-2026-AVI-1256 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1094 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0958 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:expressjs:multer:*:*:*:*:*:node.js:*:*≥ 1.0.0 < 2.2.0cpe:2.3:a:expressjs:multer:3.0.0:alpha1:*:*:*:node.js:*:*
Affected products
| Product | Versions |
|---|---|
| multer · multer | affected 1.0.0 < 2.2.0 ; unaffected 2.2.0 ; affected 3.0.0-alpha.1 < 3.0.0-alpha.2 ; unaffected 3.0.0-alpha.2 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |