multer vulnerable to Denial of Service via crafted multipart field names

CAO 7.5CVE-2026-77078 · GHSA-wc9g-mqfw-jrwm · Công bố 28/08/2026 · cập nhật 02/09/2026

Tóm tắt nhanh

CVE-2026-77078 là lỗ hổng mức CAO (CVSS 7.5) ảnh hưởng multer (expressjs), multer.
Xác suất bị khai thác trong 30 ngày tới (EPSS): 0.49%, cao hơn 42.0% các lỗ hổng khác.
Cách xử lý: cập nhật lên 2.3.0 hoặc mới hơn.

Gói / sản phẩm	Phiên bản bị ảnh hưởng	Phiên bản đã vá
multer expressjs	`< 2.3.0`	`2.3.0`
multer npm	`< 2.3.0`	`2.3.0`

Mô tả

Impact

A vulnerability in multer allows a remote, unauthenticated attacker to crash the Node.js process with a single multipart/form-data request. Two specially crafted text field names cause an uncaught RangeError: Invalid array length inside multer's field parsing, which is not routed to the application error handler and terminates the process. All applications using multer to parse multipart requests are affected.

Patches

Users should upgrade to 2.3.0.

Workarounds

None.

Mô tả của NVD

multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.