CVE-2025-15284EPSS p37.6%
CVE-2025-15284CVE-2025-15284
qs_project / qs
Description
Improper Input Validation vulnerability in qs (parse modules) allows HTTP DoS.This issue affects qs: < 6.14.1.
Summary
The arrayLimit option in qs did not enforce limits for bracket notation (a[]=1&a[]=2), only for indexed notation (a[0]=1). This is a consistency bug; arrayLimit should apply uniformly across all array notations.
Note: The default parameterLimit of 1000 effectively mitigates the DoS scenario originally described. With default options, bracket notation cannot produce arrays larger than parameterLimit regardless of arrayLimit, because each a[]=valueconsumes one parameter slot. The severity has been reduced accordingly.
Details
The arrayLimit option only checked limits for indexed notation (a[0]=1&a[1]=2) but did not enforce it for bracket notation (a[]=1&a[]=2).
Vulnerable code (lib/parse.js:159-162):
if (root === '[]' && options.parseArrays) {
obj = utils.combine([], leaf); // No arrayLimit check
}
Working code (lib/parse.js:175):
else if (index <= opt
Scoring
| CVSS | 3.7 () |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
| EPSS | 0.45% probability of exploitation · percentile 37.6% · 2026-10-17T12:00:28Z |
| Last modified | 2026-10-14 |