### Summary When `qs.parse` is called with `comma: true` and `throwOnLimitExceeded: true`, a comma-separated value under a bracket-push key (`a[]=1,2,3,4`) is split into an array without being compared against `arrayLimit`, while the same value under a flat key (`a=1,2,3,4`), an indexed key (`a[0]=`), a nested key (`a[b]=`), or a dotted key (`a.b=` with `allowDots`) throws the documented `RangeError`. A single parameter such as `a[]=1,2,2,...` therefore produces an inner array of arbitrary length even though the caller opted into the hard limit. This is the `[]=` key form that the fix for CVE-2026-2391 (qs 6.14.2) did not cover. ### Details In `lib/parse.js`, a comma-separated value under a `[]=` key is split and then wrapped as a single nested element (`val = [val]`, so that each `a[]=x,y` group counts as one element of the outer array). The `arrayLimit` check that 6.14.2 added for comma values runs after that wrap, so for `[]=` 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 `isFlatArrayValue` flag that `parseValues` set to `false` for any part containing `[]=`, and did not pass it for object-valued input, so the gap remained. #### PoC ```js var qs = require('qs'); var options = { comma: true, arrayLimit: 3, throwOnLimitExceeded: true }; qs.parse('a=1,2,3,4', options); // RangeError: Array limit exceeded. Only 3 elements allowed in an array. qs.parse('a[]=1,2,3,4', options); // { a: [ [ '1', '2', '3', '4' ] ] } (no throw) qs.parse('a[]=' + '1,'.repeat(1000000) + '1', { comma: true, arrayLimit: 20, throwOnLimitExceeded: true }); // no throw; a 1,000,001-element inner array is allocated ``` #### Fix `lib/parse.js`, applied in 8859c37 on `main` and released as v6.16.0: the `isFlatArrayValue` gate is removed, so every comma-split value is counted against `arrayLimit` before splitting regardless of key form. An in-limit group under `a[]=` still counts as one element of the outer array, and the default (`throwOnLimitExceeded: false`) path is unchanged. ### Affected versions `>=6.14.2 <6.16.0`, fixed in v6.16.0. v6.14.2 introduced `arrayLimit` enforcement for comma values (the fix for CVE-2026-2391) but only for values not under a `[]=` key, and every release from v6.14.2 through v6.15.3 has the same gap. v6.14.0 and v6.14.1, where `throwOnLimitExceeded` 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 `comma` but no `throwOnLimitExceeded`, so there is no hard cap on any comma path to bypass; releases before 6.7.0 have no `comma` option. ### Impact An unauthenticated attacker who can reach an application that parses untrusted query strings or urlencoded bodies with both `comma: true` and `throwOnLimitExceeded: true` (both non-default) can bypass the configured limit with a single `a[]=` 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 `throwOnLimitExceeded: false` path), so a transport-layer request or body size limit bounds it completely (and node's 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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - ### Summary When `qs.parse` is called with `comma: true` and `throwOnLimitExceeded: true`, a comma-
    separated value under a bracket-push key (`a[]=1,2,3,4`) is split into an array without being compared
    against `arrayLimit`, while the same value under a flat key (`a=1,2,3,4`), an indexed key (`a[0]=`), a
    nested key (`a[b]=`), or a dotted key (`a.b=` with `allowDots`) throws the documented `RangeError`. A
    single parameter such as `a[]=1,2,2,...` therefore produces an inner array of arbitrary length even though
    the caller opted into the hard limit. This is the `[]=` key form that the fix for CVE-2026-2391 (qs
    6.14.2) did not cover. ### Details In `lib/parse.js`, a comma-separated value under a `[]=` key is split
    and then wrapped as a single nested element (`val = [val]`, so that each `a[]=x,y` group counts as one
    element of the outer array). The `arrayLimit` check that 6.14.2 added for comma values runs after that
    wrap, so for `[]=` 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 `isFlatArrayValue` flag that
    `parseValues` set to `false` for any part containing `[]=`, and did not pass it for object-valued input,
    so the gap remained. #### PoC ```js var qs = require('qs'); var options = { comma: true, arrayLimit: 3,
    throwOnLimitExceeded: true }; qs.parse('a=1,2,3,4', options); // RangeError: Array limit exceeded. Only 3
    elements allowed in an array. qs.parse('a[]=1,2,3,4', options); // { a: [ [ '1', '2', '3', '4' ] ] } (no
    throw) qs.parse('a[]=' + '1,'.repeat(1000000) + '1', { comma: true, arrayLimit: 20, throwOnLimitExceeded:
    true }); // no throw; a 1,000,001-element inner array is allocated ``` #### Fix `lib/parse.js`, applied in
    8859c37 on `main` and released as v6.16.0: the `isFlatArrayValue` gate is removed, so every comma-split
    value is counted against `arrayLimit` before splitting regardless of key form. An in-limit group under
    `a[]=` still counts as one element of the outer array, and the default (`throwOnLimitExceeded: false`)
    path is unchanged. ### Affected versions `>=6.14.2 <6.16.0`, fixed in v6.16.0. v6.14.2 introduced
    `arrayLimit` enforcement for comma values (the fix for CVE-2026-2391) but only for values not under a
    `[]=` key, and every release from v6.14.2 through v6.15.3 has the same gap. v6.14.0 and v6.14.1, where
    `throwOnLimitExceeded` 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 `comma` but no `throwOnLimitExceeded`, so
    there is no hard cap on any comma path to bypass; releases before 6.7.0 have no `comma` option. ### Impact
    An unauthenticated attacker who can reach an application that parses untrusted query strings or urlencoded
    bodies with both `comma: true` and `throwOnLimitExceeded: true` (both non-default) can bypass the
    configured limit with a single `a[]=` 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
    `throwOnLimitExceeded: false` path), so a transport-layer request or body size limit bounds it completely
    (and node's 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. (CVE-2026-82562)

The remote Fedora 45 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-5c1bbb46c3 advisory.

    34.0.4 Release

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-362f1943c8 advisory.

    34.0.4 Release

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-c495e95154 advisory.

    34.0.4 Release

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - ### Summary When `qs.parse` is called with `comma: true` and `throwOnLimitExceeded: true`, a comma-     separated value under a bracket-push key (`a[]=1,2,3,4`) is split into an array without being compared     against `arrayLimit`, while the same value under a flat key (`a=1,2,3,4`), an indexed key (`a[0]=`), a     nested key (`a[b]=`), or a dotted key (`a.b=` with `allowDots`) throws the documented `RangeError`. A     single parameter such as `a[]=1,2,2,...` therefore produces an inner array of arbitrary length even though     the caller opted into the hard limit. This is the `[]=` key form that the fix for CVE-2026-2391 (qs     6.14.2) did not cover. ### Details In `lib/parse.js`, a comma-separated value under a `[]=` key is split     and then wrapped as a single nested element (`val = [val]`, so that each `a[]=x,y` group counts as one     element of the outer array). The `arrayLimit` check that 6.14.2 added for comma values runs after that     wrap, so for `[]=` 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 `isFlatArrayValue` flag that     `parseValues` set to `false` for any part containing `[]=`, and did not pass it for object-valued input,     so the gap remained. #### PoC ```js var qs = require('qs'); var options = { comma: true, arrayLimit: 3,     throwOnLimitExceeded: true }; qs.parse('a=1,2,3,4', options); // RangeError: Array limit exceeded. Only 3     elements allowed in an array. qs.parse('a[]=1,2,3,4', options); // { a: [ [ '1', '2', '3', '4' ] ] } (no     throw) qs.parse('a[]=' + '1,'.repeat(1000000) + '1', { comma: true, arrayLimit: 20, throwOnLimitExceeded:
    true }); // no throw; a 1,000,001-element inner array is allocated ``` #### Fix `lib/parse.js`, applied in     8859c37 on `main` and released as v6.16.0: the `isFlatArrayValue` gate is removed, so every comma-split     value is counted against `arrayLimit` before splitting regardless of key form. An in-limit group under     `a[]=` still counts as one element of the outer array, and the default (`throwOnLimitExceeded: false`)     path is unchanged. ### Affected versions `>=6.14.2 <6.16.0`, fixed in v6.16.0. v6.14.2 introduced     `arrayLimit` enforcement for comma values (the fix for CVE-2026-2391) but only for values not under a     `[]=` key, and every release from v6.14.2 through v6.15.3 has the same gap. v6.14.0 and v6.14.1, where     `throwOnLimitExceeded` 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 `comma` but no `throwOnLimitExceeded`, so     there is no hard cap on any comma path to bypass; releases before 6.7.0 have no `comma` option. ### Impact     An unauthenticated attacker who can reach an application that parses untrusted query strings or urlencoded     bodies with both `comma: true` and `throwOnLimitExceeded: true` (both non-default) can bypass the     configured limit with a single `a[]=` 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     `throwOnLimitExceeded: false` path), so a transport-layer request or body size limit bounds it completely     (and node's 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. (CVE-2026-82562)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
463190	Echo: qs: security update to 6.16.0	Tenable Cloud Security	Echo Local Security Checks	Local	medium
463190	Echo: qs: security update to 6.16.0	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
350860	Fedora 45 : nextcloud (2026-5c1bbb46c3)	Nessus	Fedora Local Security Checks	Local	medium
350859	Fedora 44 : nextcloud (2026-362f1943c8)	Nessus	Fedora Local Security Checks	Local	medium
350858	Fedora 43 : nextcloud (2026-c495e95154)	Nessus	Fedora Local Security Checks	Local	medium
341597	Linux Distros Unpatched Vulnerability : CVE-2026-82562	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-82562

medium

Tenable Plugins

medium

medium

medium

medium

medium

medium