Quick answers
- Is CVE-2025-47944 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2025-47944 being exploited in the wild.
- How severe is CVE-2025-47944?
- Low severity, with a CVSS score of 3.1, published 19 May 2025.
- Which products and versions are affected?
- multer (npm) SEMVER:introduced=1.4.4-lts.1,fixed=2.0.0.
- Is there a fix for CVE-2025-47944?
- Yes. multer (npm): upgrade to 2.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2025-47944 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2025-47944?
- Check whether you run multer (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- multer (npm): upgrade to 2.0.0 or later
npm install multer@2.0.0
Technical details
The vulnerability is an uncaught exception (CWE-248) in Multer's handling of malformed multipart/form-data upload requests. Specifically, an error event from the underlying busboy stream parser is not properly caught and handled, causing an unhandled exception that crashes the Node.js process. The attack requires only network access and no authentication or special privileges; an attacker can trigger the crash by sending a crafted multipart request with malformed structure. This affects all versions from 1.4.4-lts.1 to <2.0.0. The fix involves explicitly handling busboy error events and properly draining the request stream, which was addressed in version 2.0.0.
Affected products
- expressjs multer >=1.4.4-lts.1, <2.0.0
Identifiers
- CVE-2025-47944
- GHSA-4pg4-qvpc-4q3h
Timeline
- 2025-05-19: disclosed: GHSA-4pg4-qvpc-4q3h published
- 2025-05-19: patched: Version 2.0.0 released with fix