VulnerabilityAnalyzed

CVE-2026-5038

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.

HIGH 7.5EPSS 0.28%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.28% probability · 20th percentile
CISA KEV: Not listed
Weakness: CWE-459
Affected: expressjs/multer
Source: ce714d77-add3-4f53-aff5-83d477b104bb

References

https://cna.openjsf.org/security-advisories.htmlVendor Advisory
https://github.com/expressjs/multer/security/advisories/GHSA-3p4h-7m6x-2hcmVendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.