Vulnerability Description
multer is a middleware for handling multipart/form-data in Node.js. In version 2.2.0, when a disk-backed upload is aborted or truncated before the write stream finishes, multer's disk storage engine removes the visible file but does not close the underlying write file descriptor, leaving a deleted but still open descriptor. A remote attacker able to reach an upload route using the built-in disk storage can send repeated aborted or malformed multipart uploads, each one leaking a file descriptor and retaining disk blocks until the process exits, which can exhaust resources and cause a denial of service. The issue is fixed in multer 2.3.0, which closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed. Upgrade to multer 2.3.0 to remediate.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Expressjs | Multer | 2.2.0 |
Related Weaknesses (CWE)
References
- https://cna.openjsf.org/security-advisories.htmlVendor Advisory
- https://github.com/expressjs/multer/security/advisories/GHSA-qfvm-cv95-jqjfVendor Advisory
FAQ
What is CVE-2026-77037?
CVE-2026-77037 is a vulnerability with a CVSS score of 7.5 (HIGH). multer is a middleware for handling multipart/form-data in Node.js. In version 2.2.0, when a disk-backed upload is aborted or truncated before the write stream finishes, multer's disk storage engine r...
How severe is CVE-2026-77037?
CVE-2026-77037 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-77037?
Check the references section above for vendor advisories and patch information. Affected products include: Expressjs Multer.