Vulnerability · Published Oct 22, 2026 · Assigned by openjs
CVE-2026-113872multer vulnerable to Denial of Service via a pending asynchronous fileFilter after request teardown
High 7.5
In plain English
A high-severity security flaw in multer from multer. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | node-multer | 2.5.0+~cs3.3.0-1 | DEBIAN-CVE-2026-113872 |
| npm | multer | 2.5.0 | GHSA-q7qp-rjg7-q26m |
Affected products (as reported)
Weakness: CWE-248, CWE-404 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H