Quick answers
- Is CVE-2026-120439 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-120439 being exploited in the wild.
- How severe is CVE-2026-120439?
- High severity, with a CVSS score of 7, published 2 November 2026.
- Which products and versions are affected?
- QuickJS-NG before 0.16.0.
- Is there a fix for CVE-2026-120439?
- 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-2026-120439 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-120439?
- 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 in the js_typed_array_sort() function in quickjs.c fails to properly validate the allocation size when sorting typed arrays. An attacker can call TypedArray.prototype.sort with a comparator on an array near 2^30 elements, causing the size calculation to wrap and allocating a smaller buffer than required. This results in writing array indices past the allocated buffer boundary, corrupting the heap.
Affected products
- QuickJS-NG QuickJS-NG before 0.16.0
Timeline
- 2026-11-02: disclosed