High severity · published May 12, 2026
CVE-2026-8162
multiparty vulnerable to Denial of Service via Uncaught Exception in filename* parameter parsing
7.5
CVSS
0.3%
EPSS
No
On KEV
Description
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 header whose filename* parameter contains a malformed percent-encoding, the parser invokes decodeURI on the value without try/catch. The resulting URIError propagates as an uncaught exception and crashes the process. Impact: any service accepting multipart uploads via multiparty is affected. Workarounds: none. Upgrade to multiparty@4.3.0 or higher.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MU
multiparty · multiparty
through 4.2.3 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-8162
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-8162
Third Party Advisory
https://cna.openjsf.org/security-advisories.html
Vendor Advisory
https://github.com/pillarjs/multiparty/security/advisories/GHSA-xh3c-6gcq-g4rv
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