CVE-2026-3520: Expressjs Multer

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

Multer is a node.js middleware for handling `multipart/form-data`. A vulnerability in Multer prior to version 2.1.1 allows an attacker to trigger a Denial of Service (DoS) by sending malformed requests, potentially causing stack overflow. Users should upgrade to version 2.1.1 to receive a patch. No known workarounds are available.

Affected products

• Expressjs Multer: before 2.1.1 (fixed in 2.1.1)

Published 2026-03-04. Last modified 2026-07-15.