Allocation of Resources Without Limits or Throttling Affecting qs package, versions >=6.7.0 <6.14.2
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-JS-QS-15268416
- published12 Feb 2026
- disclosed12 Feb 2026
- creditSharokhAtaie
Introduced: 12 Feb 2026
NewCVE-2026-2391 (opens in a new tab)How to fix?
Upgrade qs to version 6.14.2 or higher.
Overview
qs is a querystring parser that supports nesting and arrays, with a depth limit.
Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via the parseArrayValue function when the comma option is in use. An attacker can exhaust system memory by submitting a parameter containing a large number of comma-separated values, resulting in the allocation of excessively large arrays.
Note:
This is only exploitable if the comma option is explicitly set to true. arrayLimit is properly enforced for index and bracket notation.
PoC
const qs = require('qs');
const payload = 'a=' + ','.repeat(25); // 26 elements after split (bypasses arrayLimit: 5)
const options = { comma: true, arrayLimit: 5, throwOnLimitExceeded: true };
try {
const result = qs.parse(payload, options);
console.log(result.a.length); // Outputs: 26 (bypass successful)
} catch (e) {
console.log('Limit enforced:', e.message); // Not thrown
}