Cyber Posture

CVE-2026-8159

High

Published: 12 May 2026

Published
12 May 2026
Modified
12 May 2026
KEV Added
—
Patch
—
CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0004 11.2th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-8159 is a high-severity Inefficient Regular Expression Complexity (CWE-1333) vulnerability in Openjsf (inferred from references). Its CVSS base score is 7.5 (High).

Operationally, ranked at the 11.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

NVD 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.…

more

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.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
CWE-1333

Affected Products

Openjsf
—
inferred from references and description; NVD did not file a CPE for this CVE

References