---
id: CVE-2026-113872
title: >-
  multer vulnerable to Denial of Service via a pending asynchronous fileFilter
  after request teardown
summary: >-
  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 requ…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-248
  - CWE-404
vendor: multer
product: multer
affected:
  - multer >= 2.0.0 < 2.5.0
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-22T18:26:56.734787Z'
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T19:00:31.884Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-113872'
references:
  - url: >-
      https://github.com/expressjs/multer/security/advisories/GHSA-q7qp-rjg7-q26m
  - url: 'https://cna.openjsf.org/security-advisories.html'
tags:
  - cve.org
ingestedAt: '2026-10-22T22:00:50.375Z'
---

## Overview

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.

## Affected

- `multer >= 2.0.0 < 2.5.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.