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SCA: security update for qs (GHSA-6pq8-jhm2-2vcw)

medium Tenable Self-Hosted Container Security Plugin ID 477592

Description

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

 - ### Summary `qs.stringify` with `arrayFormat: 'comma'` throws `TypeError: Cannot convert object to
 primitive value` when an array element cannot be coerced to a string, such as an object with an own non-
 callable `toString` (`{ "toString": "x" }`) or a null-prototype object. The comma format joins array
 elements with `Array.prototype.join` and, under `encodeValuesOnly`, first passes each element through
 `String()` in `utils.encode`; neither guards against an element whose string coercion fails. ### Details
 In `lib/stringify.js`, the comma branch collapses the array with `obj.join(',')`. For an element whose own
 `toString` is not callable, `ToPrimitive` skips it, falls through to `Object.prototype.valueOf` (which
 returns the object itself), and throws. Under `encodeValuesOnly: true`, the same element first reaches
 `String(str)` in `utils.encode` (`lib/utils.js`) and throws there. Nested arrays (`{ "a": [[{ "toString":
 "x" }]] }`) throw the same way, through `Array.prototype.toString`. The `indices`, `brackets`, and
 `repeat` formats walk into object elements instead of coercing them, and are not affected. Such elements
 can come from untrusted input. `JSON.parse` produces `{ "a": [{ "toString": "x" }] }` with no qs option
 involved. `qs.parse("a[0][toString]=x", { allowPrototypes: true })` keeps the `toString` key, and
 `qs.parse("a[][b]=c", { plainObjects: true })` produces a null-prototype element; the default parse
 options drop `toString` and produce ordinary objects, which do not throw. Express 4's default `query
 parser`, Express 5's `extended` query parser, and body-parser's `urlencoded({ extended: true })` all call
 `qs.parse` with `allowPrototypes: true`. #### PoC ```js var qs = require("qs");
 qs.stringify(JSON.parse("{\"a\":[{\"toString\":\"x\"}]}"), { arrayFormat: "comma" });
 qs.stringify(qs.parse("a[0][toString]=x", { allowPrototypes: true }), { arrayFormat: "comma" });
 qs.stringify(qs.parse("a[][b]=c", { plainObjects: true }), { arrayFormat: "comma", encodeValuesOnly: true
 }); // TypeError: Cannot convert object to primitive value ``` #### Fix Applied in a952e75 on `main` and
 released as v6.16.1: an element whose string coercion would fail is coerced to its primitive `valueOf`, if
 any, or else to `Object.prototype.toString`, so it renders as `[object Object]`, the same as any other
 object element already does under the comma format. Nested arrays are walked the way `join` walks them.
 Every input that did not previously throw serializes exactly as before, and a `toString` or `valueOf` that
 itself throws still propagates. ### Affected versions `>=6.7.0 <6.16.1`, fixed in v6.16.1. The `join` path
 was introduced with the comma format in b84acba and first shipped in v6.7.0; v6.6.x and earlier ignore
 `arrayFormat: 'comma'` and are not affected. The `encodeValuesOnly` `String()` site was introduced in
 4c4b23d (v6.11.1); before that, the same input throws at `join`. Every release from v6.7.0 through v6.16.0
 is affected. ### Impact An unauthenticated request can make any code path that re-serializes attacker-
 influenced data with `qs.stringify` and `arrayFormat: 'comma'` (for example, rebuilding a query string
 from `req.query` for a redirect or an upstream request, or serializing a parsed JSON body) throw
 synchronously. In a typical Node.js HTTP framework the throw is caught by the framework error boundary and
 the affected request returns a 500; the process survives and other requests are unaffected. Where the call
 runs outside an error boundary, such as an `async` Express 4 handler (where the throw becomes an unhandled
 promise rejection) or a bare `http` request handler, the process exits, so the impact in that case depends
 on the application error handling rather than on qs. The default `arrayFormat` (`indices`) is not
 affected. (CVE-2026-110816)

Solution

Update the qs library and its related packages to version 6.16.1 or later.

See Also

https://github.com/advisories/GHSA-6pq8-jhm2-2vcw

Plugin Details

Severity: Medium

ID: 477592

Version: Revision 1.1

Type: Local

Family: SCA Checks

Published: 10/27/2026

Updated: 10/27/2026

Risk Information

VPR

Risk Factor: Low

Score: 3.9

Percentile: 52.43

Vendor

Vendor Severity: Medium

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2026-110816

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: Medium

Base Score: 6.3

Threat Score: 1.7

Threat Vector: CVSS:4.0/E:U

Vector: 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

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 10/27/2026

Vulnerability Publication Date: 10/14/2026

Reference Information

CVE: CVE-2026-110816