CVE-2025-15284 (High) detected in qs-6.13.0.tgz, qs-6.14.0.tgz

[mend-bolt-for-github]

CVE-2025-15284 - High Severity Vulnerability

Vulnerable Libraries - qs-6.13.0.tgz, qs-6.14.0.tgz

qs-6.13.0.tgz

Library home page: https://registry.npmjs.org/qs/-/qs-6.13.0.tgz

Path to dependency file: /ui/package.json

Path to vulnerable library: /ui/package.json

Dependency Hierarchy:

• @postgres.ai/ce-4.0.2.tgz (Root Library)
  • react-scripts-5.0.1.tgz
    • webpack-dev-server-4.15.2.tgz
      • express-4.21.2.tgz
        • ❌ qs-6.13.0.tgz (Vulnerable Library)

qs-6.14.0.tgz

A querystring parser that supports nesting and arrays, with a depth limit

Library home page: https://registry.npmjs.org/qs/-/qs-6.14.0.tgz

Path to dependency file: /ui/package.json

Path to vulnerable library: /ui/package.json

Dependency Hierarchy:

• @postgres.ai/ce-4.0.2.tgz (Root Library)
  • cypress-14.5.4.tgz
    • request-3.0.9.tgz
      • ❌ qs-6.14.0.tgz (Vulnerable Library)

Found in base branch: master

Vulnerability Details

Improper Input Validation vulnerability in qs (parse modules) allows HTTP DoS.This issue affects qs: < 6.14.1.
SummaryThe arrayLimit option in qs does not enforce limits for bracket notation (a[]=1&a[]=2), allowing attackers to cause denial-of-service via memory exhaustion. Applications using arrayLimit for DoS protection are vulnerable.
DetailsThe arrayLimit option only checks limits for indexed notation (a[0]=1&a[1]=2) but completely bypasses 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.
PoCTest 1 - Basic bypass:
npm install qs
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)
Test 2 - DoS demonstration:
const qs = require('qs');
const attack = 'a[]=' + Array(10000).fill('x').join('&a[]=');
const result = qs.parse(attack, { arrayLimit: 100 });
console.log(result.a.length); // Output: 10000 (should be max 100)
Configuration:

• arrayLimit: 5 (test 1) or arrayLimit: 100 (test 2)
• Use bracket notation: a[]=value (not indexed a[0]=value)
  ImpactDenial of Service via memory exhaustion. Affects applications using qs.parse() with user-controlled input and arrayLimit for protection.
  Attack scenario:
• Attacker sends HTTP request: GET /api/search?filters[]=x&filters[]=x&...&filters[]=x (100,000+ times)
• Application parses with qs.parse(query, { arrayLimit: 100 })
• qs ignores limit, parses all 100,000 elements into array
• Server memory exhausted → application crashes or becomes unresponsive
• Service unavailable for all users
  Real-world impact:
• Single malicious request can crash server
• No authentication required
• Easy to automate and scale
• Affects any endpoint parsing query strings with bracket notation

Publish Date: 2025-12-29

URL: CVE-2025-15284

CVSS 3 Score Details (7.5)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: GHSA-6rw7-vpxm-498p

Release Date: 2025-12-29

Fix Resolution: qs - 6.14.1,qs - 6.14.1,https://github.com/ljharb/qs.git - v6.14.1

---

Step up your Open Source Security Game with Mend here