195 lines
12 KiB
JSON
195 lines
12 KiB
JSON
{
|
||
"dataType": "CVE_RECORD",
|
||
"dataVersion": "5.2",
|
||
"cveMetadata": {
|
||
"cveId": "CVE-2026-2391",
|
||
"assignerOrgId": "7ffcee3d-2c14-4c3e-b844-86c6a321a158",
|
||
"state": "PUBLISHED",
|
||
"assignerShortName": "harborist",
|
||
"dateReserved": "2026-02-12T03:52:09.332Z",
|
||
"datePublished": "2026-02-12T04:39:42.914Z",
|
||
"dateUpdated": "2026-02-12T17:32:05.953Z"
|
||
},
|
||
"containers": {
|
||
"cna": {
|
||
"affected": [
|
||
{
|
||
"collectionURL": "https://npmjs.com/qs",
|
||
"defaultStatus": "unaffected",
|
||
"packageName": "qs",
|
||
"repo": "https://github.com/ljharb/qs",
|
||
"versions": [
|
||
{
|
||
"lessThanOrEqual": "6.14.1",
|
||
"status": "affected",
|
||
"version": "6.7.0",
|
||
"versionType": "semver"
|
||
}
|
||
]
|
||
}
|
||
],
|
||
"descriptions": [
|
||
{
|
||
"lang": "en",
|
||
"supportingMedia": [
|
||
{
|
||
"base64": false,
|
||
"type": "text/html",
|
||
"value": "### Summary<br>The `arrayLimit` option in qs does not enforce limits for comma-separated values when `comma: true` is enabled, allowing attackers to cause denial-of-service via memory exhaustion. This is a bypass of the array limit enforcement, similar to the bracket notation bypass addressed in GHSA-6rw7-vpxm-498p (CVE-2025-15284).<br><br>### Details<br>When the `comma` option is set to `true` (not the default, but configurable in applications), qs allows parsing comma-separated strings as arrays (e.g., `?param=a,b,c` becomes `['a', 'b', 'c']`). However, the limit check for `arrayLimit` (default: 20) and the optional throwOnLimitExceeded occur after the comma-handling logic in `parseArrayValue`, enabling a bypass. This permits creation of arbitrarily large arrays from a single parameter, leading to excessive memory allocation.<br><br>**Vulnerable code** (lib/parse.js: lines ~40-50):<br>```js<br>if (val && typeof val === 'string' && options.comma && val.indexOf(',') > -1) {<br> return val.split(',');<br>}<br><br>if (options.throwOnLimitExceeded && currentArrayLength >= options.arrayLimit) {<br> throw new RangeError('Array limit exceeded. Only ' + options.arrayLimit + ' element' + (options.arrayLimit === 1 ? '' : 's') + ' allowed in an array.');<br>}<br><br>return val;<br>```<br>The `split(',')` returns the array immediately, skipping the subsequent limit check. Downstream merging via `utils.combine` does not prevent allocation, even if it marks overflows for sparse arrays.This discrepancy allows attackers to send a single parameter with millions of commas (e.g., `?param=,,,,,,,,...`), allocating massive arrays in memory without triggering limits. It bypasses the intent of `arrayLimit`, which is enforced correctly for indexed (`a[0]=`) and bracket (`a[]=`) notations (the latter fixed in v6.14.1 per GHSA-6rw7-vpxm-498p).<br><br>### PoC<br>**Test 1 - Basic bypass:**<br>```<br>npm install qs<br>```<br><br>```js<br>const qs = require('qs');<br><br>const payload = 'a=' + ','.repeat(25); // 26 elements after split (bypasses arrayLimit: 5)<br>const options = { comma: true, arrayLimit: 5, throwOnLimitExceeded: true };<br><br>try {<br> const result = qs.parse(payload, options);<br> console.log(result.a.length); // Outputs: 26 (bypass successful)<br>} catch (e) {<br> console.log('Limit enforced:', e.message); // Not thrown<br>}<br>```<br>**Configuration:**<br>- `comma: true`<br>- `arrayLimit: 5`<br>- `throwOnLimitExceeded: true`<br><br>Expected: Throws \"Array limit exceeded\" error.<br>Actual: Parses successfully, creating an array of length 26.<br><br><br>### Impact<br>Denial of Service (DoS) via memory exhaustion.<br>"
|
||
}
|
||
],
|
||
"value": "### Summary\nThe `arrayLimit` option in qs does not enforce limits for comma-separated values when `comma: true` is enabled, allowing attackers to cause denial-of-service via memory exhaustion. This is a bypass of the array limit enforcement, similar to the bracket notation bypass addressed in GHSA-6rw7-vpxm-498p (CVE-2025-15284).\n\n### Details\nWhen the `comma` option is set to `true` (not the default, but configurable in applications), qs allows parsing comma-separated strings as arrays (e.g., `?param=a,b,c` becomes `['a', 'b', 'c']`). However, the limit check for `arrayLimit` (default: 20) and the optional throwOnLimitExceeded occur after the comma-handling logic in `parseArrayValue`, enabling a bypass. This permits creation of arbitrarily large arrays from a single parameter, leading to excessive memory allocation.\n\n**Vulnerable code** (lib/parse.js: lines ~40-50):\n```js\nif (val && typeof val === 'string' && options.comma && val.indexOf(',') > -1) {\n return val.split(',');\n}\n\nif (options.throwOnLimitExceeded && currentArrayLength >= options.arrayLimit) {\n throw new RangeError('Array limit exceeded. Only ' + options.arrayLimit + ' element' + (options.arrayLimit === 1 ? '' : 's') + ' allowed in an array.');\n}\n\nreturn val;\n```\nThe `split(',')` returns the array immediately, skipping the subsequent limit check. Downstream merging via `utils.combine` does not prevent allocation, even if it marks overflows for sparse arrays.This discrepancy allows attackers to send a single parameter with millions of commas (e.g., `?param=,,,,,,,,...`), allocating massive arrays in memory without triggering limits. It bypasses the intent of `arrayLimit`, which is enforced correctly for indexed (`a[0]=`) and bracket (`a[]=`) notations (the latter fixed in v6.14.1 per GHSA-6rw7-vpxm-498p).\n\n### PoC\n**Test 1 - Basic bypass:**\n```\nnpm install qs\n```\n\n```js\nconst qs = require('qs');\n\nconst payload = 'a=' + ','.repeat(25); // 26 elements after split (bypasses arrayLimit: 5)\nconst options = { comma: true, arrayLimit: 5, throwOnLimitExceeded: true };\n\ntry {\n const result = qs.parse(payload, options);\n console.log(result.a.length); // Outputs: 26 (bypass successful)\n} catch (e) {\n console.log('Limit enforced:', e.message); // Not thrown\n}\n```\n**Configuration:**\n- `comma: true`\n- `arrayLimit: 5`\n- `throwOnLimitExceeded: true`\n\nExpected: Throws \"Array limit exceeded\" error.\nActual: Parses successfully, creating an array of length 26.\n\n\n### Impact\nDenial of Service (DoS) via memory exhaustion."
|
||
}
|
||
],
|
||
"impacts": [
|
||
{
|
||
"capecId": "CAPEC-130",
|
||
"descriptions": [
|
||
{
|
||
"lang": "en",
|
||
"value": "CAPEC-130 Excessive Allocation"
|
||
}
|
||
]
|
||
}
|
||
],
|
||
"metrics": [
|
||
{
|
||
"cvssV4_0": {
|
||
"Automatable": "NOT_DEFINED",
|
||
"Recovery": "NOT_DEFINED",
|
||
"Safety": "NOT_DEFINED",
|
||
"attackComplexity": "LOW",
|
||
"attackRequirements": "PRESENT",
|
||
"attackVector": "NETWORK",
|
||
"baseScore": 6.3,
|
||
"baseSeverity": "MEDIUM",
|
||
"exploitMaturity": "NOT_DEFINED",
|
||
"privilegesRequired": "NONE",
|
||
"providerUrgency": "NOT_DEFINED",
|
||
"subAvailabilityImpact": "NONE",
|
||
"subConfidentialityImpact": "NONE",
|
||
"subIntegrityImpact": "NONE",
|
||
"userInteraction": "NONE",
|
||
"valueDensity": "NOT_DEFINED",
|
||
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
|
||
"version": "4.0",
|
||
"vulnAvailabilityImpact": "LOW",
|
||
"vulnConfidentialityImpact": "NONE",
|
||
"vulnIntegrityImpact": "NONE",
|
||
"vulnerabilityResponseEffort": "NOT_DEFINED"
|
||
},
|
||
"format": "CVSS",
|
||
"scenarios": [
|
||
{
|
||
"lang": "en",
|
||
"value": "GENERAL"
|
||
}
|
||
]
|
||
},
|
||
{
|
||
"cvssV3_1": {
|
||
"attackComplexity": "HIGH",
|
||
"attackVector": "NETWORK",
|
||
"availabilityImpact": "LOW",
|
||
"baseScore": 3.7,
|
||
"baseSeverity": "LOW",
|
||
"confidentialityImpact": "NONE",
|
||
"integrityImpact": "NONE",
|
||
"privilegesRequired": "NONE",
|
||
"scope": "UNCHANGED",
|
||
"userInteraction": "NONE",
|
||
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
|
||
"version": "3.1"
|
||
},
|
||
"format": "CVSS",
|
||
"scenarios": [
|
||
{
|
||
"lang": "en",
|
||
"value": "GENERAL"
|
||
}
|
||
]
|
||
}
|
||
],
|
||
"problemTypes": [
|
||
{
|
||
"descriptions": [
|
||
{
|
||
"cweId": "CWE-20",
|
||
"description": "CWE-20 Improper Input Validation",
|
||
"lang": "en",
|
||
"type": "CWE"
|
||
}
|
||
]
|
||
}
|
||
],
|
||
"providerMetadata": {
|
||
"orgId": "7ffcee3d-2c14-4c3e-b844-86c6a321a158",
|
||
"shortName": "harborist",
|
||
"dateUpdated": "2026-02-12T17:32:05.953Z"
|
||
},
|
||
"references": [
|
||
{
|
||
"tags": [
|
||
"vendor-advisory"
|
||
],
|
||
"url": "https://github.com/ljharb/qs/security/advisories/GHSA-w7fw-mjwx-w883"
|
||
},
|
||
{
|
||
"tags": [
|
||
"patch"
|
||
],
|
||
"url": "https://github.com/ljharb/qs/commit/f6a7abff1f13d644db9b05fe4f2c98ada6bf8482"
|
||
}
|
||
],
|
||
"source": {
|
||
"discovery": "UNKNOWN"
|
||
},
|
||
"title": "qs's arrayLimit bypass in comma parsing allows denial of service",
|
||
"x_generator": {
|
||
"engine": "Vulnogram 0.5.0"
|
||
}
|
||
},
|
||
"adp": [
|
||
{
|
||
"references": [
|
||
{
|
||
"url": "https://github.com/ljharb/qs/security/advisories/GHSA-w7fw-mjwx-w883",
|
||
"tags": [
|
||
"exploit"
|
||
]
|
||
}
|
||
],
|
||
"metrics": [
|
||
{
|
||
"other": {
|
||
"type": "ssvc",
|
||
"content": {
|
||
"timestamp": "2026-02-12T15:00:21.359233Z",
|
||
"id": "CVE-2026-2391",
|
||
"options": [
|
||
{
|
||
"Exploitation": "poc"
|
||
},
|
||
{
|
||
"Automatable": "yes"
|
||
},
|
||
{
|
||
"Technical Impact": "partial"
|
||
}
|
||
],
|
||
"role": "CISA Coordinator",
|
||
"version": "2.0.3"
|
||
}
|
||
}
|
||
}
|
||
],
|
||
"title": "CISA ADP Vulnrichment",
|
||
"providerMetadata": {
|
||
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
|
||
"shortName": "CISA-ADP",
|
||
"dateUpdated": "2026-02-12T15:00:40.388Z"
|
||
}
|
||
}
|
||
]
|
||
}
|
||
} |