Vulnerability details

CVE-2026-77037

multer multer

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

CVSS 3.1
7.5High

Official description

multer is a middleware for handling multipart/form-data in Node.js. In version 2.2.0, when a disk-backed upload is aborted or truncated before the write stream finishes, multer's disk storage engine removes the visible file but does not close the underlying write file descriptor, leaving a deleted but still open descriptor. A remote attacker able to reach an upload route using the built-in disk storage can send repeated aborted or malformed multipart uploads, each one leaking a file descriptor and retaining disk blocks until the process exits, which can exhaust resources and cause a denial of service. The issue is fixed in multer 2.3.0, which closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed. Upgrade to multer 2.3.0 to remediate.

CVSS scores

ScoreVersionSourceVector
7.5High 3.1 CVEProject cvelistV5 (CNA) (openjs) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

VendorProductVersionsSource
multer multer 2.2.0 ≤ v < 2.3.0 CVEProject cvelistV5 (CNA)

References and advisories

2
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Details

Published
2026-08-28
Last updated
2026-08-31
State
Published
Assigner (CNA)
openjs

Exploit prediction (EPSS)

0.45%
Probability of exploitation in 30 days
39.8%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
Yes
Exploitation
None
Technical impact
Partial

Weaknesses (CWE)

  • CWE-400
    Uncontrolled Resource Consumption
  • CWE-459
    Incomplete Cleanup