multer is a middleware for Node.js that handles multipart/form-data file uploads. In versions from 2.0.0 before 2.5.0, when multer is configured with an asynchronous fileFilter, a single request can crash the Node.js process. If the request is aborted while one file's asynchronous fileFilter is still pending, the pending callback later resumes a parsing stream that multer has already torn down, and the underlying parser emits an error on a stream that no longer has an error listener, which Node raises as an unhandled error event so the process exits. Any application using multer with an asynchronous fileFilter is affected regardless of storage engine, while uploads using a synchronous fileFilter are not affected. The issue is fixed in multer 2.5.0, and users should upgrade to 2.5.0 or later. As a workaround, use a synchronous fileFilter.
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History

Thu, 22 Oct 2026 15:45:00 +0000

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

Thu, 22 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Description multer is a middleware for Node.js that handles multipart/form-data file uploads. In versions from 2.0.0 before 2.5.0, when multer is configured with an asynchronous fileFilter, a single request can crash the Node.js process. If the request is aborted while one file's asynchronous fileFilter is still pending, the pending callback later resumes a parsing stream that multer has already torn down, and the underlying parser emits an error on a stream that no longer has an error listener, which Node raises as an unhandled error event so the process exits. Any application using multer with an asynchronous fileFilter is affected regardless of storage engine, while uploads using a synchronous fileFilter are not affected. The issue is fixed in multer 2.5.0, and users should upgrade to 2.5.0 or later. As a workaround, use a synchronous fileFilter.
Title multer vulnerable to Denial of Service via a pending asynchronous fileFilter after request teardown
Weaknesses CWE-248
CWE-404
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'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: openjs

Published:

Updated: 2026-10-22T14:20:18.363Z

Reserved: 2026-10-20T19:59:25.159Z

Link: CVE-2026-113872

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-22T15:17:05.377

Modified: 2026-10-22T15:25:10.067

Link: CVE-2026-113872

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-22T16:45:09Z

Weaknesses