Vulnerability · Published Nov 2, 2026 · Assigned by VulnCheck

CVE-2026-120438QuickJS-NG before 0.16.0 Heap Buffer Overflow via Proxy ownKeys Enumeration

High 7.8

In plain English

A high-severity integer overflow in QuickJS-NG from quickjs-ng. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High

Exploit odds (30 days)0.1%top 96.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

QuickJS-NG before 0.16.0 contains an integer overflow in js_proxy_get_own_property_names() in quickjs.c that causes a heap buffer overflow on 32-bit hosts. Attackers running JavaScript can return a large array-like object from a Proxy ownKeys trap to wrap the allocation size, causing crashes or potential code execution.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:14	quickjs-ng	0.16.2-1	DEBIAN-CVE-2026-120438
Ubuntu:26.10	quickjs-ng	no fix listed	UBUNTU-CVE-2026-120438

Affected products (as reported)

Vendor	Product	Versions
quickjs-ng	QuickJS-NG	0 – before 0.16.0

Weakness: CWE-190 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

GitHub Security Advisory (GHSA-jp52-chwg-2p9p) vendor-advisory
https://github.com/quickjs-ng/quickjs/commit/252209d99cf112568160548bdcaa98d95e0d0068 patch
QuickJS-NG v0.16.0 Release Notes release-notes
https://github.com/quickjs-ng/quickjs/blob/v0.15.1/quickjs.c#L51509 technical-description
VulnCheck Advisory: QuickJS-NG before 0.16.0 Heap Buffer Overflow via Proxy ownKeys Enumeration third-party-advisory