cvedb.io
CVE-2026-5079
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-06-15T14:16:37.293 · Last modified 2026-06-17T10:58:24.257

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 li

Affected products

expressjs — multer

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.