multiparty vulnerable to Denial of Service via Uncaught Exception in filename* parameter parsing — CVE-2026-8162

Summary

### Impact multiparty@4.2.3 and lower versions are vulnerable to denial of service via uncaught exception. By sending a `multipart/form-data` request with a `Content-Disposition: filename*=utf-8''` header containing a malformed percent-encoding (e.g., `%FF`, `%GG`), the parser invokes `decodeURI` on the value without try/catch. The resulting `URIError` propagates as an uncaught exception and crashes the process.…

Product

npm: multiparty

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Related advisories