3.7

CVE-2026-77063

multer vulnerable to file size limit bypass via async fileFilter race condition

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Expressjs ≫ Multer SwPlatform node.js Version < 2.3.0
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.17% 0.066
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
ce714d77-add3-4f53-aff5-83d477b104bb 3.7 2.2 1.4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

https://cna.openjsf.org/security-advisories.html
Vendor Advisory
https://github.com/expressjs/multer/security/advisories/GHSA-qvfw-j98x-7q72
Vendor Advisory
Mitigation