Quick answers
- Is CVE-2026-120438 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-120438 being exploited in the wild.
- How severe is CVE-2026-120438?
- High severity, with a CVSS score of 7.8, published 2 November 2026.
- Which products and versions are affected?
- QuickJS-NG before 0.16.0.
- Is there a fix for CVE-2026-120438?
- Yes: fixed in 0.16.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-120438 attacked?
- It is attacked over the network or with local access, in a software library.
- Am I affected by CVE-2026-120438?
- Check whether you run QuickJS-NG at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 0.16.0
Technical details
An integer overflow exists in js_proxy_get_own_property_names() in quickjs.c when handling Proxy ownKeys traps that return objects with very large length values on 32-bit hosts. A malicious JavaScript snippet can return a specially crafted array-like object from the Proxy trap that wraps the allocation size calculation, triggering a heap buffer overflow. The vulnerability requires the ability to execute JavaScript code against the QuickJS-NG runtime.
Affected products
- QuickJS-NG QuickJS-NG before 0.16.0
Timeline
- 2026-11-02: disclosed