DEBIAN-CVE-2026-82417
### Summary `qs.stringify` throws a `TypeError` when it serializes an object whose own `constructor` property has a truthy, non-callable `isBuffer` member. `utils.isBuffer` duck-types buffers by calling `obj.constructor.isBuffer(obj)` after checking only that the property is truthy, so a value such as `{ constructor: { isBuffer: "x" } }` makes the call throw `TypeError: obj.constructor.isBuffer is not a function`. ### Details `lib/stringify.js:127` calls `utils.isBuffer` on every non-primitive value it serializes. `utils.isBuffer` (`lib/utils.js:332`) reads `obj.constructor.isBuffer` and invokes it without verifying that it is a function. `constructor` and `isBuffer` are ordinary property names, so any object carrying them as own properties reaches the unchecked call. Such an object can be built from untrusted input. `qs.parse("x[constructor][isBuffer]=y", { plainObjects: true })` or `{ allowPrototypes: true }` keeps the `constructor` key as an own property (the default parse options drop it), and `JSON.parse("{\"a\":{\"constructor\":{\"isBuffer\":\"x\"}}}")` produces the same shape with no qs option involved. Express 4 with its default `query parser` setting and body-parser with `extended: true` both call `qs.parse` with `allowPrototypes: true`, so on those stacks `req.query` and `req.body` can carry the shape directly. #### PoC ```js var qs = require("qs"); qs.stringify(qs.parse("x[constructor][isBuffer]=y", { plainObjects: true })); qs.stringify(JSON.parse("{\"a\":{\"const
DEBIAN-CVE-2026-82417
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-82417
node-qs
Source reference: /affected/0/package/name
- Affected versions
- 6.11.0+ds+~6.9.7-3
Source reference:
/affected/0/versions6.11.0+ds+~6.9.7-4Source reference:
/affected/0/versions6.13.0+ds+~6.9.16-1Source reference:
/affected/0/versions6.14.1+ds+~6.14.0-1Source reference:
/affected/0/versions6.15.0+ds+~6.15.0-1Source reference:
/affected/0/versions6.15.0+ds+~6.15.0-2Source reference:
/affected/0/versions6.15.0+ds+~6.15.0-3Source reference:
/affected/0/versions6.15.2+ds+~6.15.1-1Source reference:
/affected/0/versions6.16.0+ds+~6.15.1-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
node-qs
Source reference: /affected/1/package/name
- Affected versions
- 6.13.0+ds+~6.9.16-1
Source reference:
/affected/1/versions6.14.1+ds+~6.14.0-1Source reference:
/affected/1/versions6.15.0+ds+~6.15.0-1Source reference:
/affected/1/versions6.15.0+ds+~6.15.0-2Source reference:
/affected/1/versions6.15.0+ds+~6.15.0-3Source reference:
/affected/1/versions6.15.2+ds+~6.15.1-1Source reference:
/affected/1/versions6.16.0+ds+~6.15.1-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
node-qs
Source reference: /affected/2/package/name
- Affected versions
- 6.13.0+ds+~6.9.16-1
Source reference:
/affected/2/versions6.14.1+ds+~6.14.0-1Source reference:
/affected/2/versions6.15.0+ds+~6.15.0-1Source reference:
/affected/2/versions6.15.0+ds+~6.15.0-2Source reference:
/affected/2/versions6.15.0+ds+~6.15.0-3Source reference:
/affected/2/versions6.15.2+ds+~6.15.1-1Source reference:
/affected/2/versions - Fixed versions
- 6.16.0+ds+~6.15.1-1
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-qs",
"purl": "pkg:deb/debian/node-qs?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"6.11.0+ds+~6.9.7-3",
"6.11.0+ds+~6.9.7-4",
"6.13.0+ds+~6.9.16-1",
"6.14.1+ds+~6.14.0-1",
"6.15.0+ds+~6.15.0-1",
"6.15.0+ds+~6.15.0-2",
"6.15.0+ds+~6.15.0-3",
"6.15.2+ds+~6.15.1-1",
"6.16.0+ds+~6.15.1-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-82417.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-qs",
"purl": "pkg:deb/debian/node-qs?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"6.13.0+ds+~6.9.16-1",
"6.14.1+ds+~6.14.0-1",
"6.15.0+ds+~6.15.0-1",
"6.15.0+ds+~6.15.0-2",
"6.15.0+ds+~6.15.0-3",
"6.15.2+ds+~6.15.1-1",
"6.16.0+ds+~6.15.1-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-82417.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.16.0+ds+~6.15.1-1"
}
]
}
],
"package": {
"name": "node-qs",
"purl": "pkg:deb/debian/node-qs?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"6.13.0+ds+~6.9.16-1",
"6.14.1+ds+~6.14.0-1",
"6.15.0+ds+~6.15.0-1",
"6.15.0+ds+~6.15.0-2",
"6.15.0+ds+~6.15.0-3",
"6.15.2+ds+~6.15.1-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-82417.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #58486 · Revision 1
- Added to Heist Feed
- Publisher date