qs: Denial of Service via Attacker Controlled isBuffer — GHSA-4MJR-XMP4-GH2G

Summary

### Summary `qs.stringify()` calls `utils.isBuffer()` on every value it serializes, and `utils.isBuffer()` invokes `obj.constructor.isBuffer(obj)` without checking that it is callable. A value whose own `constructor.isBuffer` is a non-function makes `qs` call a non-callable and throw `TypeError`. Such a value is produced **by `qs.parse` itself** from an untrusted query string when `plainObjects: true` or…

Timeline

Published by source

2026-09-02

Risk context

• Reported severity or threat level: medium.
• Reported CVSS score: 6.3 out of 10.
• Reported EPSS value: 0.00261.
• Review exposure for the affected product or family: npm: qs.

Product

npm: qs

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-4MJR-XMP4-GH2G

Source

GitHub

Vendor

GitHub

Published by source

2026-09-02

Last source activity

2026-09-02

Additional identifiers

CVE-2026-82417

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.