Bug 2542080

Summary: CVE-2026-77037 fido-device-onboard: Multer: Denial of Service via file descriptor leak on aborted uploads [fedora-all]
Product: [Fedora] Fedora Reporter: nlevinki <nlevinki>
Component: fido-device-onboardAssignee: Peter Robinson <pbrobinson>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: go-sig, miabbott, pbrobinson
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["cfb861ba-c972-48cc-a0cf-09dba0abfd81"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2525787    

Description nlevinki 2026-09-27 14:15:51 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.