# CVE-2025-15284: arrayLimit bypass in bracket notation allows DoS via memory exhaustion

> CVE-2025-15284: arrayLimit bypass in bracket notation allows DoS via memory exhaustion. CVSS 3.7 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2025-15284
Last updated: 2026-10-14T19:10:00Z

- Published: 2025-12-29 22:56 UTC · Updated: 2026-10-14 19:10 UTC · Assigner: harborist
- CVSS: 3.7 (CVSS 3.1) · Severity: Low · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
- EPSS: 0.45%, 39th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-20

## 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 \<= options.arrayLimit) {  // Limit checked here     obj = \[\];     obj\[index\] = leaf; } The bracket notation handler at line 159 uses utils.combine(\[\], leaf) without validating against options.arrayLimit, while indexed notation at line 175 checks index \<= options.arrayLimit before creating arrays. PoC const qs = require('qs'); const result = qs.parse('a\[\]=1&a\[\]=2&a\[\]=3&a\[\]=4&a\[\]=5&a\[\]=6', { arrayLimit: 5 }); console.log(result.a.length);  // Output: 6 (should be max 5) Note on parameterLimit interaction: The original advisory's "DoS demonstration" claimed a length of 10,000, but parameterLimit (default: 1000) caps parsing to 1,000 parameters. With default options, the actual output is 1,000, not 10,000. Impact Consistency bug in arrayLimit enforcement. With default parameterLimit, the practical DoS risk is negligible since parameterLimit already caps the total number of parsed parameters (and thus array elements from bracket notation). The risk increases only when parameterLimit is explicitly set to a very high value.

## Affected vendors and products

_None listed._

## Tracked companies

- [Jira](https://rewindex.com/company/jira.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2025-15284)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2025-15284)
- [https://github.com/ljharb/qs/commit/3086902ecf7f088d0d1803887643ac6c03d415b9](https://github.com/ljharb/qs/commit/3086902ecf7f088d0d1803887643ac6c03d415b9)
- [https://github.com/ljharb/qs/security/advisories/GHSA-6rw7-vpxm-498p](https://github.com/ljharb/qs/security/advisories/GHSA-6rw7-vpxm-498p)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2025-15284 · Markdown: https://rewindex.com/cve/CVE-2025-15284.md · JSON: https://rewindex.com/api/v1/cves/CVE-2025-15284 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:25.329Z