---
title: "CVE-2026-66078\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-2026-66078?format=md
keywords: index, follow
---

# CVE-2026-66078

Publication date 29 September 2026

Last updated 29 September 2026

---

Ubuntu priority

**Medium**

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

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## Description

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and
4.0.20 and 4.1.11 and 4.2.6, protected tag bypass via bulk-delete. dELETE
/api/users/:name refuses to delete users tagged protected
(rabbitmgmtwmuser:deleteresource/2 checks isprotecteduser). POST
/api/users/bulk-delete iterates the supplied username list and calls
rabbitauthbackendinternal:deleteuser/2 directly , that function has no
protected-tag check , so the guard is silently An administrator can delete
protected-tagged service accounts via the bulk endpoint, bypassing a
safeguard the test suite confirms is rabbitmqmanagement enabled Attacker
has the administrator tag A protected-tagged user. This issue is fixed in
versions 3.13.15 and 4.0.20 and 4.1.11 and 4.2.6.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| rabbitmq-server | 26.04 LTS resolute | Needs evaluation |
| 24.04 LTS noble | Needs evaluation |
| 22.04 LTS jammy | Needs evaluation |
| 20.04 LTS focal | Needs evaluation |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |

---

* [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

**Base score**

2.1 · Low

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 2.1 · Low |
  | Base + Threat score | - |
  | Base + Environmental score | - |
  | Base + Threat + Environmental score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-66078)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-66078)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-66078)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-66078)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-66078>
* <https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-j9m2-hw6x-rqr9>
* <https://github.com/rabbitmq/rabbitmq-server/commit/e5b890a64b42ec1f79a8e9d735512150cf77479c>
* <https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6>