CVE-2026-5038

Summary

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 Software

VendorProductVersion RangeStatus
multermulter2.0.0-alpha.1 < 2.2.0affected
multermulter2.2.0unaffected
multermulter3.0.0-alpha.1 < 3.0.0-alpha.2affected
multermulter3.0.0-alpha.2unaffected

Weaknesses

  • CWE-459: CWE-459: Incomplete Cleanup

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References