Integer overflow in Quickjs-Ng
CVE-2026-120438
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.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/quickjs-ng/quickjs/security/advisories/GHSA-jp52-chwg-2p9p (vendor-advisory)
- github.com/quickjs-ng/quickjs/commit/252209d99cf112568160548bdcaa98d95e0d0068 (patch)
- github.com/quickjs-ng/quickjs/releases/tag/v0.16.0 (release-notes)
- github.com/quickjs-ng/quickjs/blob/v0.15.1/quickjs.c (technical-description)
- www.vulncheck.com/advisories/quickjs-ng-before-0.16.0-heap-buffer-overflow-via-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-120438?
- CVE-2026-120438 is a high-severity vulnerability in Quickjs-Ng, classified under Integer Overflow or Wraparound. CVSS score: 7.8/10. Published 2026-11-02.
- How severe is CVE-2026-120438?
- High severity. CVSS v3 base score is 7.8 out of 10.