CVE-2026-77078

multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://cna.openjsf.org/security-advisories.html	Vendor Advisory
https://github.com/expressjs/multer/security/advisories/GHSA-wc9g-mqfw-jrwm	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:expressjs:multer:*:*:*:*:*:node.js:*:*

History

No history.

Information

Published : 2026-08-28 22:16

Updated : 2026-09-02 14:46

NVD link : CVE-2026-77078

Mitre link : CVE-2026-77078

CVE.ORG link : CVE-2026-77078

JSON object : View

Products Affected

expressjs

multer

CWE

CWE-248

Uncaught Exception

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