Express-FileUpload Arbitrary File OverwriteGHSA-w4m6-x6c2-j5c9
HIGHGHSA-w4m6-x6c2-j5c9 is a high-severity (CVSS 7.5) Unrestricted File Upload vulnerability in express-fileupload. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
express-fileuploadnpmDescription
An arbitrary file write vulnerability in Express-FileUpload v1.3.1 allows attackers to upload multiple files with the same name, causing an overwrite of files in the web application server. This vulnerability is debated by the package author.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | express-fileupload | all versions | No fix |
Affected Products
express-fileuploadexpress-fileupload_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for express-fileupload, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of express-fileupload for GHSA-w4m6-x6c2-j5c9. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve.
Frequently Asked Questions
Is GHSA-w4m6-x6c2-j5c9 in your dependencies?
Find it across npm, including transitive dependencies.