multer is a middleware for handling multipart/form-data in Node.js. In version 2.2.0, when a disk-backed upload is aborted or truncated before the write stream finishes, multer's disk storage engine removes the visible file but does not close the underlying write file descriptor, leaving a deleted but still open descriptor. A remote attacker able to reach an upload route using the built-in disk storage can send repeated aborted or malformed multipart uploads, each one leaking a file descriptor and retaining disk blocks until the process exits, which can exhaust resources and cause a denial of service. The issue is fixed in multer 2.3.0, which closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed. Upgrade to multer 2.3.0 to remediate.
History

Sat, 29 Aug 2026 00:30:00 +0000

Type Values Removed Values Added
First Time appeared Multer
Multer multer
Vendors & Products Multer
Multer multer

Fri, 28 Aug 2026 22:00:00 +0000

Type Values Removed Values Added
Description multer is a middleware for handling multipart/form-data in Node.js. In version 2.2.0, when a disk-backed upload is aborted or truncated before the write stream finishes, multer's disk storage engine removes the visible file but does not close the underlying write file descriptor, leaving a deleted but still open descriptor. A remote attacker able to reach an upload route using the built-in disk storage can send repeated aborted or malformed multipart uploads, each one leaking a file descriptor and retaining disk blocks until the process exits, which can exhaust resources and cause a denial of service. The issue is fixed in multer 2.3.0, which closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed. Upgrade to multer 2.3.0 to remediate.
Title multer vulnerable to Denial of Service via file descriptor leak on aborted uploads
Weaknesses CWE-400
CWE-459
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: openjs

Published:

Updated: 2026-08-28T19:44:23.501Z

Reserved: 2026-08-20T09:01:08.767Z

Link: CVE-2026-77037

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-28T22:16:53.627

Modified: 2026-08-28T22:16:53.627

Link: CVE-2026-77037

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-29T00:15:05Z