HIGH7.5
GHSA-wc9g-mqfw-jrwm
multer vulnerable to Denial of Service via crafted multipart field names
Quick fix
GHSA-wc9g-mqfw-jrwm — multer: upgrade to the fixed version with the command below.
npm install multer@2.3.0Details
### 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.
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://github.com/expressjs/multer/security/advisories/GHSA-wc9g-mqfw-jrwm[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-77078[ADVISORY]
- https://github.com/expressjs/multer/commit/87a584e8c8d4da873292635fa1d8c4d78d985b76[WEB]
- https://cna.openjsf.org/security-advisories.html[WEB]
- https://github.com/expressjs/multer[PACKAGE]
- https://github.com/expressjs/multer/releases/tag/v2.3.0[WEB]