{
  "cveId": "CVE-2026-82562",
  "url": "https://patchblox.com/security/cve/CVE-2026-82562",
  "summary": "CVE-2026-82562 is fixed in node-qs on 1 platform by DEBIAN-CVE-2026-82562 (version 6.16.0\u002Bds\u002B~6.15.1-1), released September 4, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "node-qs: ### Summary    When \u0060qs.parse\u0060 is called with \u0060comma: true\u0060 and \u0060throwOnLimitExceeded: true\u0060, a comma-separated value...",
  "description": "### Summary    When \u0060qs.parse\u0060 is called with \u0060comma: true\u0060 and \u0060throwOnLimitExceeded: true\u0060, a comma-separated value under a bracket-push key (\u0060a[]=1,2,3,4\u0060) is split into an array without being compared against \u0060arrayLimit\u0060, while the same value under a flat key (\u0060a=1,2,3,4\u0060), an indexed key (\u0060a[0]=\u0060), a nested key (\u0060a[b]=\u0060), or a dotted key (\u0060a.b=\u0060 with \u0060allowDots\u0060) throws the documented \u0060RangeError\u0060. A single parameter such as \u0060a[]=1,2,2,...\u0060 therefore produces an inner array of arbitrary length even though the caller opted into the hard limit. This is the \u0060[]=\u0060 key form that the fix for CVE-2026-2391 (qs 6.14.2) did not cover.    ### Details    In \u0060lib/parse.js\u0060, a comma-separated value under a \u0060[]=\u0060 key is split and then wrapped as a single nested element (\u0060val = [val]\u0060, so that each \u0060a[]=x,y\u0060 group counts as one element of the outer array). The \u0060arrayLimit\u0060 check that 6.14.2 added for comma values runs after that wrap, so for \u0060[]=\u0060 parts it only ever saw the wrapper of length 1. 6.15.3 added a pre-split comma count so that an oversized value throws before it is allocated, but gated it on an \u0060isFlatArrayValue\u0060 flag that \u0060parseValues\u0060 set to \u0060false\u0060 for any part containing \u0060[]=\u0060, and did not pass it for object-valued input, so the gap remained.    #### PoC    \u0060\u0060\u0060js    var qs = require(\u0027qs\u0027);    var options = { comma: true, arrayLimit: 3, throwOnLimitExceeded: true };    qs.parse(\u0027a=1,2,3,4\u0027, options);   // RangeError: Array limit exceeded. Only 3 elements allowed in an array.    qs.parse(\u0027a[]=1,2,3,4\u0027, options); // { a: [ [ \u00271\u0027, \u00272\u0027, \u00273\u0027, \u00274\u0027 ] ] }  (no throw)    qs.parse(\u0027a[]=\u0027 \u002B \u00271,\u0027.repeat(1000000) \u002B \u00271\u0027, { comma: true, arrayLimit: 20, throwOnLimitExceeded: true });    // no throw; a 1,000,001-element inner array is allocated    \u0060\u0060\u0060    #### Fix    \u0060lib/parse.js\u0060, applied in 8859c37 on \u0060main\u0060 and released as v6.16.0: the \u0060isFlatArrayValue\u0060 gate is removed, so every comma-split value is counted against \u0060arrayLimit\u0060 before splitting regardless of key form. An in-limit group under \u0060a[]=\u0060 still counts as one element of the outer array, and the default (\u0060throwOnLimitExceeded: false\u0060) path is unchanged.    ### Affected versions    \u0060\u003E=6.14.2 \u003C6.16.0\u0060, fixed in v6.16.0.    v6.14.2 introduced \u0060arrayLimit\u0060 enforcement for comma values (the fix for CVE-2026-2391) but only for values not under a \u0060[]=\u0060 key, and every release from v6.14.2 through v6.15.3 has the same gap. v6.14.0 and v6.14.1, where \u0060throwOnLimitExceeded\u0060 exists but does not apply to any comma form, are covered by CVE-2026-2391 rather than this record. Earlier lines (6.7.x through 6.13.x) have \u0060comma\u0060 but no \u0060throwOnLimitExceeded\u0060, so there is no hard cap on any comma path to bypass; releases before 6.7.0 have no \u0060comma\u0060 option.    ### Impact    An unauthenticated attacker who can reach an application that parses untrusted query strings or urlencoded bodies with both \u0060comma: true\u0060 and \u0060throwOnLimitExceeded: true\u0060 (both non-default) can bypass the configured limit with a single \u0060a[]=\u0060 parameter and force the parser to allocate an array proportional to the request size. The cost is strictly linear in the attacker-supplied bytes (about 0.1 microseconds and 6 to 7 retained bytes per input byte; the same out-of-memory threshold as the documented default \u0060throwOnLimitExceeded: false\u0060 path), so a transport-layer request or body size limit bounds it completely (and node\u0027s default maximum HTTP header size of 16 KB already bounds the request line, so multi-megabyte payloads need a body parser). The impact is that an opt-in hard limit fails open on one key spelling, not unbounded allocation from a small input.",
  "published": "2026-08-30T01:20:32Z",
  "severity": "",
  "epss": 0.0054,
  "epssPercentile": 0.45703,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "node-qs",
      "release": "Debian 14",
      "fixedVersion": "6.16.0\u002Bds\u002B~6.15.1-1",
      "fix": "DEBIAN-CVE-2026-82562",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-82562",
      "released": "2026-09-04T01:46:23Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}