What is CVE-2026-5079?

CVE-2026-5079 is a high-severity vulnerability in Expressjs Multer, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-06-15.

How severe is CVE-2026-5079?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Expressjs Multer

CVE-2026-5079

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 n…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.003 (20.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Expressjs Multer — versions 3.0.0
Multer — versions 1.0.0, 2.2.0, 3.0.0-alpha.1

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

ce714d77-add3-4f53-aff5-83d477b104bb (Vendor Advisory)
ce714d77-add3-4f53-aff5-83d477b104bb (Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-5079?: CVE-2026-5079 is a high-severity vulnerability in Expressjs Multer, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-06-15.
How severe is CVE-2026-5079?: High severity. CVSS v3 base score is 7.5 out of 10.