# CVE-2026-120439: QuickJS-NG before 0.16.0 Heap Buffer Overflow via TypedArray.prototype.sort

Status: published. Published: 2026-11-02. Updated: 2026-11-02.

QuickJS-NG before 0.16.0 contains an integer overflow in js_typed_array_sort() in quickjs.c that allows attackers to cause a heap buffer overflow on 32-bit hosts. Attackers who can run JavaScript can call TypedArray.prototype.sort with a comparator on a typed array near 2^30 elements, wrapping the allocation size and writing indices past the buffer to crash or potentially execute code.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- quickjs-ng / QuickJS-NG (quickjs-ng/quickjs): ≥ 0; < 0.16.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.3 (high); CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 7 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-190

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/quickjs-ng/quickjs/security/advisories/GHSA-9wv5-5cgr-grj6 (CNA: VulnCheck; vendor-advisory)

- https://github.com/quickjs-ng/quickjs/commit/e93cca611908e12b824ec85fbee6b31a5ee61568 (CNA: VulnCheck; patch)

- https://github.com/quickjs-ng/quickjs/releases/tag/v0.16.0 (CNA: VulnCheck; release-notes)

- https://github.com/quickjs-ng/quickjs/blob/v0.15.1/quickjs.c#L60032 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/quickjs-ng-before-0.16.0-heap-buffer-overflow-via-typedarray-prototype-sort (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-120439; retrieved 2026-11-02; source updated 2026-11-02

Revision: 842068cd2669eca63c0f74b041b56fadccca3d62c059b23db5a60cf40c39e40e

Canonical: https://y2.dev/cve/CVE-2026-120439

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