Packages / multer / Security

HighVulnerabilityGHSA-qfvm-cv95-jqjfCVE-2026-77037Published 8 Sep 2026

multer vulnerable to Denial of Service via file descriptor leak on aborted uploads

Your version

Affected releases · multer

  • 2.x2.2.0Fixed in 2.3.0

On 2.x, the newest line:

npm install multer@2.3.0
Every release on a timeline

  1. Not affected

    0.0.1 – 2.1.1

    37 releases

  2. Affected

    2.2.0

    1 release

  3. Fixed

    2.3.0 – 2.5.0

    3 releases, latest

41 stable releases of multer, oldest to newest.

What happens

Impact

A vulnerability in multer 2.2.0 allows an attacker to trigger a Denial of Service (DoS) by aborting or truncating multipart uploads. When using diskStorage, the destination write stream is not closed if the upload is aborted before it finishes, so each failed request leaks an open file descriptor and retains its disk blocks until the process exits. Repeated failed uploads can exhaust the available file descriptors. All applications using multer's disk storage are affected.

Patches

Users should upgrade to 2.3.0.

Workarounds

None.