HIGH

CVE-2026-3520

Multer vulnerable to Denial of Service via uncontrolled recursion

CVSS v3

7.5

HIGH

EPSS Score

1.0 %

exploit probability, as of 2026-10-19

CISA KEV

known exploited

Exploitation

none

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

multernpmall versions · fixed in 2.1.1

Vendor advisories

CVE-2026-3520 Red Hat Product Security2 products fixed · 1 known affected
multer: Multer: Denial of Service via malformed requests
ansible-automation-platform/automation-portal as a component of Self-service automation portal 2
RHSA-2026:6802 Red Hat Product Security1 product fixed
Red Hat Security Advisory: Red Hat Developer Hub 1.9.3 release.
RHSA-2026:6174 Red Hat Product Security1 product fixed
Red Hat Security Advisory: Red Hat Developer Hub 1.8.5 release.

Full record on NVD

Description

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.

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2026-03-04
Last Modified: 2026-03-09

Frequently asked questions

What is CVE-2026-3520?

Is CVE-2026-3520 actively exploited?

Active exploitation of CVE-2026-3520 has not been confirmed. Its EPSS score was 1.0% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-3520?

CVE-2026-3520 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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