# CVE-2026-77063: node-multer: multer is a middleware for handling multipart/form-data in Node.js

CVE-2026-77063 is fixed in node-multer on 1 platform by DEBIAN-CVE-2026-77063 (version 2.4.0+~cs3.2.0-1), released August 28, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-77063
- Priority: Routine
- CVSS: 3.7 (low)
- EPSS: 0.0023
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 28, 2026

## Description

multer is a middleware for handling multipart/form-data in Node.js. When an application uses an asynchronous fileFilter together with the fileSize limit, a race condition in multer's file stream handling can allow a file that exceeds the configured size limit to bypass the size-limit rejection. All versions before 2.3.0 are affected. The impact is limited because the underlying multipart parser still truncates the stream at the size limit, so this is a bypass of the limit rejection rather than uncontrolled resource consumption. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-multer Debian 14 | 2.4.0+~cs3.2.0-1 | [DEBIAN-CVE-2026-77063](https://patchblox.com/security/data/fix/linux/debian-cve-2026-77063.md) | Aug 28, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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