Vulnerability record · CVE-2026-5038 · published 15 June 2026
CVE-2026-5038: Expressjs multer vulnerability
Expressjs · Multer
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.
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://cna.openjsf.org/security-advisories.html | Vendor Advisory |
| https://github.com/expressjs/multer/security/advisories/GHSA-3p4h-7m6x-2hcm | Vendor Advisory |
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-5038), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.