CVE-2025-47944: Multer vulnerable to Denial of Service from maliciously crafted requests

Published May 19, 2025
·
Updated

Impact A vulnerability in Multer versions >=1.4.4-lts.1 allows an attacker to trigger a Denial of Service (DoS) by sending a malformed multi-part upload request. This request causes an unhandled exception, leading to a crash of the process.

Patches Users should upgrade to 2.0.0

Workarounds None

References

- https://github.com/expressjs/multer/issues/1176 - https://github.com/expressjs/multer/commit/2c8505f207d923dd8de13a9f93a4563e59933665

Other sources

Multer is a node.js middleware for handling multipart/form-data. A vulnerability that is present starting in version 1.4.4-lts.1 and prior to version 2.0.0 allows an attacker to trigger a Denial of Service (DoS) by sending a malformed multi-part upload request. This request causes an unhandled exception, leading to a crash of the process. Users should upgrade to version 2.0.0 to receive a patch. No known workarounds are available.

MITRE

Affected Software

3 affected componentsFixes available
Multer Multer>=1.4.4-lts.1, <2.0.0
npm/multer>=1.4.4-lts.1<2.0.0
2.0.0
IBM Concert Software<=1.0.0-1.1.0

Event History

May 19, 2025
CVE Published
via MITRE·07:20 PM
Data Sourced
via MITRE·07:20 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·08:15 PM
DescriptionSeverityWeakness
Advisory Published
via GitHub·10:16 PM
Nov 3, 2025
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2025-47944?

CVE-2025-47944 has been assigned a critical severity due to its potential to cause a Denial of Service (DoS) attack.

2

How do I fix CVE-2025-47944?

To fix CVE-2025-47944, upgrade Multer to version 2.0.0 or later.

3

Which versions of Multer are affected by CVE-2025-47944?

CVE-2025-47944 affects Multer versions from 1.4.4-lts.1 up to but not including 2.0.0.

4

What type of vulnerability is CVE-2025-47944?

CVE-2025-47944 is a Denial of Service (DoS) vulnerability triggered by malformed multi-part upload requests.

5

Can CVE-2025-47944 affect my application?

If your application uses Multer versions within the affected range, it is susceptible to CVE-2025-47944 and may experience service disruption.

Contact

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