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CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-77078

multer vulnerable to Denial of Service via crafted multipart field names

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

multer multer

Default version status: unaffected

  • 0 to < 2.3.0affected
  • 2.3.0unaffected
pkg:npm/multer

References