---
title: "CVE-2026-120439: QuickJS-NG - Integer Overflow"
description: "QuickJS-NG < 0.16.0 contains an integer overflow in js_typed_array_sort() in quickjs.c, letting attackers running JavaScript cause heap buffer overflow on 32-bit hosts by sorting large typed arrays with a comparator."
url: https://panop.io/threat-heartbeat/CVE-2026-120439/
---

# CVE-2026-120439 QuickJS-NG - Integer Overflow

QuickJS-NG < 0.16.0 contains an integer overflow in js\_typed\_array\_sort() in quickjs.c, letting attackers running JavaScript cause heap buffer overflow on 32-bit hosts by sorting large typed arrays with a comparator.

CVSS base score 7.0 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-120439)

## Details

Type

Integer Overflow

Impact

Remote Code Execution, Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

Published

2 November 2026

Updated

3 November 2026

Weakness

[CWE-190](https://cwe.mitre.org/data/definitions/190.html)

## Vendor fix

Update to version 0.16.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-120439](https://nvd.nist.gov/vuln/detail/CVE-2026-120439)
- [https://github.com/quickjs-ng/quickjs/releases/tag/v0.16.0](https://github.com/quickjs-ng/quickjs/releases/tag/v0.16.0)
- [https://github.com/quickjs-ng/quickjs/security/advisories/GHSA-9wv5-5cgr-grj6](https://github.com/quickjs-ng/quickjs/security/advisories/GHSA-9wv5-5cgr-grj6)
- [https://www.vulncheck.com/advisories/quickjs-ng-before-0.16.0-heap-buffer-overflow-via-typedarray-prototype-sort](https://www.vulncheck.com/advisories/quickjs-ng-before-0.16.0-heap-buffer-overflow-via-typedarray-prototype-sort)
- [https://github.com/quickjs-ng/quickjs/blob/v0.15.1/quickjs.c#L60032](https://github.com/quickjs-ng/quickjs/blob/v0.15.1/quickjs.c#L60032)
- [https://github.com/quickjs-ng/quickjs/commit/e93cca611908e12b824ec85fbee6b31a5ee61568](https://github.com/quickjs-ng/quickjs/commit/e93cca611908e12b824ec85fbee6b31a5ee61568)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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