DoS via malformed multipart/form-data in Multer <2.1.0
CVE-2026-3304 Published on February 27, 2026

Multer vulnerable to Denial of Service via incomplete cleanup
Multer is a node.js middleware for handling `multipart/form-data`. A vulnerability in Multer prior to version 2.1.0 allows an attacker to trigger a Denial of Service (DoS) by sending malformed requests, potentially causing resource exhaustion. Users should upgrade to version 2.1.0 to receive a patch. No known workarounds are available.

Github Repository NVD

Vulnerability Analysis

CVE-2026-3304 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

What is an Insufficient Cleanup Vulnerability?

The software does not properly "clean up" and remove temporary or supporting resources after they have been used.

CVE-2026-3304 has been classified to as an Insufficient Cleanup vulnerability or weakness.


Products Associated with CVE-2026-3304

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Red Hat Rhdh
 
Red Hat Ansible Portal
 
Red Hat Logging
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Trusted Profile Analyzer
 

Affected Versions

expressjs multer: Red Hat Developer Hub 1.8: Red Hat Developer Hub 1.9: Red Hat Self-service automation portal 2: Logging Subsystem for Red Hat OpenShift: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Trusted Profile Analyzer:

Vulnerable Packages

The following package name and versions may be associated with CVE-2026-3304

Package Manager Vulnerable Package Versions Fixed In
npm multer < 2.1.0 2.1.0

Exploit Probability

EPSS
0.56%
Percentile
41.87%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.