CVE-2026-5038 Details
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.
A denial-of-service vulnerability has been identified in multer, affecting versions 2.0.0-alpha.1 prior to 2.2.0, and 3.0.0-alpha.1 prior to 3.0.0-alpha.2. The issue arises when diskStorage is used, as aborted or malformed multipart uploads leave behind orphaned partial files on disk. This occurs because the Readable.pipe() function does not properly transmit the stream destroy signal to the underlying fs.WriteStream, allowing an attacker to fill up disk space by causing numerous uploads to be aborted.
Users are advised to upgrade to multer version 2.2.0 or 3.0.0-alpha.2. Both versions include the necessary fix by tracking in-flight write streams and cleaning them up when an upload is aborted.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 15, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://cna.openjsf.org/security-advisories.html | openjs | Vendor Advisory |
| https://github.com/expressjs/multer/security/advisories/GHSA-3p4h-7m6x-2hcm | openjs | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-459 | Incomplete Cleanup | openjs |
Affected Products
| Product | Versions |
|---|---|
| expressjs multer | >= 2.0.0, < 2.2.0 3.0.0 alpha1 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | openjs |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 16, 2026 | Initial Analysis | [email protected] |
| Jun 15, 2026 | New CVE Received | openjs |