---
title: "CVE-2023-6840\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-2023-6840?format=md
keywords: index, follow
---

# CVE-2023-6840

Publication date 7 February 2024

Last updated 26 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**6.7 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2023-6840?format=md#impact-score)

Toggle side navigation

## Description

An issue has been discovered in GitLab EE affecting all versions from 16.4
prior to 16.6.7, 16.7 prior to 16.7.5, and 16.8 prior to 16.8.2 which
allows a maintainer to change the name of a protected branch that bypasses
the security policy added to block MR.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| gitlab | 24.04 LTS noble | Not in release |
| 23.10 mantic | Not in release |
| 22.04 LTS jammy | Not in release |
| 20.04 LTS focal | Not in release |
| 18.04 LTS bionic | Not in release |
| 16.04 LTS xenial | Ignored end of standard support |
| 14.04 LTS trusty | 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 v3.0

**Base score**

6.7 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | High |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | Low |
  | Integrity impact | High |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 6.7 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-6840)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2023-6840)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2023-6840)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2023-6840)

### Other references

* <https://about.gitlab.com/releases/2024/02/07/security-release-gitlab-16-8-2-released/#project-maintainers-can-bypass-groups-scan-result-policy-block_branch_modification-setting>
* <https://gitlab.com/gitlab-org/gitlab/-/issues/435500>
* <https://hackerone.com/reports/2280292>
* <https://www.cve.org/CVERecord?id=CVE-2023-6840>