multiparty@4.2.3 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 multiparty@4.3.0 or higher.
History

Tue, 12 May 2026 13:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 12 May 2026 09:30:00 +0000

Type Values Removed Values Added
Description multiparty@4.2.3 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 multiparty@4.3.0 or higher.
Title multiparty vulnerable to ReDoS via filename parsing
Weaknesses CWE-1333
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: openjs

Published:

Updated: 2026-05-12T12:33:59.418Z

Reserved: 2026-05-08T09:45:28.532Z

Link: CVE-2026-8159

cve-icon Vulnrichment

Updated: 2026-05-12T12:33:56.826Z

cve-icon NVD

Status : Received

Published: 2026-05-12T10:16:48.857

Modified: 2026-05-12T10:16:48.857

Link: CVE-2026-8159

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-12T10:45:14Z