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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.002 (4.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
- Quickjs-Ng Quickjs — versions 0.12.0, 0.12.1
Weakness classification (CWE)
References
- vuldb.com/ (technical-description, vdb-entry)
- vuldb.com/ (signature, permissions-required)
- vuldb.com/ (third-party-advisory)
- github.com/quickjs-ng/quickjs/issues/1368 (issue-tracking)
- github.com/quickjs-ng/quickjs/pull/1370 (issue-tracking, patch)
- github.com/quickjs-ng/quickjs/issues/1368 (issue-tracking, exploit)
- github.com/quickjs-ng/quickjs/commit/daab4ad4bae4ef071ed0294618d6244e92def4cd (patch)
- github.com/quickjs-ng/quickjs/ (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.