---
title: "CVE-2026-3979\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2026-3979?format=md
keywords: index, follow
---

# CVE-2026-3979

Publication date 12 March 2026

Last updated 10 July 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**5.3 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2026-3979?format=md#impact-score)

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## Description

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.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| quickjs | 26.04 LTS resolute | Needs evaluation |
| 25.10 questing | Ignored end of life, was needs-triage |
| 24.04 LTS noble | Needs evaluation |
| 22.04 LTS jammy | Not in release |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:

CVSS v4.0

[CVSS v4.0](https://ubuntu.com/security/CVE-2026-3979?format=md)
[CVSS v3.0](https://ubuntu.com/security/CVE-2026-3979?format=md)

**Base score**

1.9 · Low

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Local |
  | Attack complexity | Low |
  | Attack requirements | None |
  | Privileges required | Low |
  | User interaction | None |
  | Vulnerable system - Confidentiality impact | Low |
  | Vulnerable system - Integrity impact | Low |
  | Vulnerable system - Availability impact | Low |
  | Subsequent system - Confidentiality impact | None |
  | Subsequent system - Integrity impact | None |
  | Subsequent system - Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 1.9 · Low |
  | Base + Threat score | - |
  | Base + Environmental score | - |
  | Base + Threat + Environmental score | - |

**Vector:** CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-3979)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-3979)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-3979)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-3979)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-3979>