What is CVE-2026-3979?

CVE-2026-3979 is a medium-severity vulnerability in Quickjs-Ng Quickjs, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.3/10. Published 2026-03-12.

How severe is CVE-2026-3979?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Buffer overflow in Quickjs-Ng Quickjs

CVE-2026-3979

A flaw has been found in quickjs-ng quickjs up to 0.12.1. This affects the function js_iterator_concat_return of the file quickjs.c. This manipulation causes use after free. The attack requires local access. The exploit has been published and may be used. Patch name: daab4ad4bae4ef071ed0294618d6244e92def4cd. Applying a patch is the recommended action to fix this issue.

Vulnerability class: Buffer Overflow

EPSS: 0.001 (1.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

Affected products

Quickjs-ng Quickjs — versions 0.12.0, 0.12.1

Weakness classification (CWE)

References

cna@vuldb.com (technical-description, vdb-entry)
cna@vuldb.com (signature, permissions-required)
cna@vuldb.com (third-party-advisory)
cna@vuldb.com (issue-tracking)
cna@vuldb.com (issue-tracking, patch)
cna@vuldb.com (issue-tracking, exploit)
cna@vuldb.com (patch)
cna@vuldb.com (product)

Frequently asked questions

What is CVE-2026-3979?: CVE-2026-3979 is a medium-severity vulnerability in Quickjs-Ng Quickjs, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.3/10. Published 2026-03-12.
How severe is CVE-2026-3979?: Medium severity. CVSS v3 base score is 5.3 out of 10.