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