multer vulnerable to Denial of Service via orphaned disk writes on aborted uploads

中 5.3CVE-2026-88932 · GHSA-3pph-fpjx-jg34 · 14/09/2026 公開 · 16/09/2026 更新

要点

CVE-2026-88932 は multer に影響する深刻度「中」 (CVSS 5.3) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.53%（全脆弱性の 45.0% より高い）。
対処：2.4.0 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
multer npm	`≥ 2.2.0, < 2.4.0`	`2.4.0`

概要

Impact

Multer's diskStorage can leave complete, orphaned files on disk when a multipart upload is aborted in the brief window before the storage engine assigns the file path. This is an incomplete fix of CVE-2026-5038: the earlier cleanup removes only in-flight uploads that already have a path, so an upload aborted inside that window is written to disk with nothing left to remove it, and the application is not given a handle to clean it up. An unauthenticated attacker sending aborted requests to any route backed by disk storage can accumulate orphaned files until the upload directory or the shared system temporary directory is exhausted. An asynchronous destination or filename widens the window.

Patches

Users should upgrade to 2.4.0 or higher.

Workarounds

None.

NVD の説明

multer is a Node.js middleware for handling multipart/form-data uploads. In versions 2.2.0 through 2.3.0, when a request using disk storage is aborted mid-upload, file writes that complete after multer has already run its abort cleanup are not removed, so each aborted upload can leave an orphaned file on disk. A remote unauthenticated attacker can repeatedly start and abort uploads to accumulate orphaned files and exhaust disk space, causing a denial of service. The issue is fixed in multer 2.4.0, and users should upgrade to 2.4.0 or later.