---
id: CVE-2026-120440
title: QuickJS-NG before 0.16.0 Memory Leak via Atomics.store
summary: >-
  QuickJS-NG before 0.16.0 contains a memory leak vulnerability in
  js_atomics_store() in quickjs.c that fails to free the converted value when
  returning a RangeError. Attackers running JavaScript can repeatedly call
  Atomics.store with a va…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-401
vendor: quickjs-ng
product: QuickJS-NG
affected:
  - QuickJS-NG < 0.16.0
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-11-02T17:12:52.060134Z'
published: '2026-11-02'
updated: '2026-11-02'
sourceUpdated: '2026-11-02T17:33:29.004Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-120440'
references:
  - url: >-
      https://github.com/quickjs-ng/quickjs/security/advisories/GHSA-wm7w-r6qf-3c9w
    label: GitHub Security Advisory (GHSA-wm7w-r6qf-3c9w)
  - url: >-
      https://github.com/quickjs-ng/quickjs/commit/62951e1bc68711d37aad986ff84ef0fe17038a7e
  - url: 'https://github.com/quickjs-ng/quickjs/releases/tag/v0.16.0'
    label: QuickJS-NG v0.16.0 Release Notes
  - url: 'https://github.com/quickjs-ng/quickjs/blob/v0.15.1/quickjs.c#L61154'
  - url: >-
      https://www.vulncheck.com/advisories/quickjs-ng-before-0.16.0-memory-leak-via-atomics-store
    label: 'VulnCheck Advisory: QuickJS-NG before 0.16.0 Memory Leak via Atomics.store'
tags:
  - cve.org
epss: 0.00469
epssPercentile: 0.40791
ingestedAt: '2026-11-05T19:30:42.732Z'
---

## Overview

QuickJS-NG before 0.16.0 contains a memory leak vulnerability in js_atomics_store() in quickjs.c that fails to free the converted value when returning a RangeError. Attackers running JavaScript can repeatedly call Atomics.store with a valueOf that detaches or shrinks the buffer to exhaust heap memory and cause denial of service.

## Affected

- `QuickJS-NG < 0.16.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.