CVE-2026-8159

HIGH

multiparty vulnerable to ReDoS via filename parsing

Title source: cna
STIX 2.1

Description

[email protected] and lower versions are vulnerable to denial of service via regular expression backtracking in the Content-Disposition filename parameter parser. A crafted multipart upload with a long header value can cause regex matching to take seconds, blocking the event loop. Impact: any service accepting multipart uploads via multiparty is affected. Workarounds: limiting upload sizes at the proxy or gateway layer reduces but does not eliminate the attack surface, since a small header of around 8 KB is sufficient to trigger the vulnerable backtracking. Upgrade to [email protected] or higher.

Scores

CVSS v3 7.5
EPSS 0.0006
EPSS Percentile 17.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-1333
Status published
Products (4)
multiparty/multiparty < 4.2.3
multiparty/multiparty 4.3.0
npm/multiparty 0 - 4.3.0npm
pillarjs/multiparty < 4.3.0
Published May 12, 2026
Tracked Since May 12, 2026