Multer is a node.js middleware for handling `multipart/form-data`. A vulnerability in Multer prior to version 2.1.1 allows an attacker to trigger a Denial of Service (DoS) by sending malformed requests, potentially causing stack overflow. Users should upgrade to version 2.1.1 to receive a patch.
No known workarounds are available.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://cna.openjsf.org/security-advisories.html
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https://github.com/expressjs/multer/commit/7e66481f8b2e6c54b982b34c152479e096ce…
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https://github.com/expressjs/multer/security/advisories/GHSA-5528-5vmv-3xc2
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https://www.cve.org/CVERecord?id=CVE-2026-3520
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