Bug 2559046 (CVE-2026-113872)

Summary: CVE-2026-113872 multer: multer: Denial of Service via aborted request during asynchronous file filtering
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: abarbaro, akostadi, alizardo, amasferr, dmayorov, dschmidt, jchui, jhe, jlanda, jlledo, kshier, ktsao, nboldt, oaljalju, pantinor, psrna, rbobbitt, simaishi, stcannon, tsedmik, yguenane
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in multer. A remote attacker could cause a Denial of Service (DoS) by sending and abruptly aborting a file upload request when an asynchronous file filter is configured. When the aborted request's pending filter callback finishes, it triggers an unhandled stream error, leading to an application process crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-22 14:31:58 UTC 
multer is a middleware for Node.js that handles multipart/form-data file uploads. In versions from 2.0.0 before 2.5.0, when multer is configured with an asynchronous fileFilter, a single request can crash the Node.js process. If the request is aborted while one file's asynchronous fileFilter is still pending, the pending callback later resumes a parsing stream that multer has already torn down, and the underlying parser emits an error on a stream that no longer has an error listener, which Node raises as an unhandled error event so the process exits. Any application using multer with an asynchronous fileFilter is affected regardless of storage engine, while uploads using a synchronous fileFilter are not affected. The issue is fixed in multer 2.5.0, and users should upgrade to 2.5.0 or later. As a workaround, use a synchronous fileFilter.