Vulnerability · Published Jun 15, 2026 · Assigned by openjs
CVE-2026-5038multer vulnerable to Denial of Service via incomplete cleanup of aborted uploads
Medium 5.3
In plain English
A medium-severity security flaw in multer from multer. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Impact: multer versions 2.0.0-alpha.1 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service when using diskStorage. Aborted or malformed multipart uploads leave orphaned partial files on disk because the Readable.pipe() call does not propagate the stream destroy signal to the underlying fs.WriteStream. An attacker can exhaust disk space by triggering many aborted uploads, with no application bug required. Patches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease). Both versions track in-flight write streams and clean them up on the abort path. Workarounds: None.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | multer | 2.2.0 | GHSA-3p4h-7m6x-2hcm |
| npm | multer | 3.0.0-alpha.2 | GHSA-3p4h-7m6x-2hcm |
Affected products (as reported)
Weakness: CWE-459 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L