CVE-2025-48997 Multer vulnerable to Denial of Service via unhandled exception
An attacker can crash the application by sending a multipart upload with an empty field name, causing an unhandled exception.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-48997?
CVE-2025-48997 is a high-severity denial of service vulnerability in expressjs multer, published on 3 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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 2.0.1 allows an attacker to trigger a Denial of Service (DoS) by sending an upload file request with an empty string field name. This request causes an unhandled exception, leading to a crash of the process. Users should upgrade to `2.0.1` to receive a patch. No known workarounds are available.
Weakness: CWE-248
Which versions are affected by CVE-2025-48997?
2 open source packages ship an affected version, including multer.
| Package | Affected | Fixed in |
|---|---|---|
multer npm | From 1.4.4-lts.1 | 2.0.1 |
multer npm | From 1.4.4-lts.1 | 2.0.1 |
How do I fix CVE-2025-48997?
Upgrade multer to 2.0.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-48997 being exploited?
There is no known exploitation of CVE-2025-48997 in the wild and no public exploit code.
Sources
Also known as ECHO-05c8-97e7-5c87, GHSA-g5hg-p3ph-g8qg, MINI-qmch-926m-x8qr, ROOT-APP-NPM-CVE-2025-48997.