# CVE-2026-66078: rabbitmq-server: RabbitMQ is a messaging and streaming broker

CVE-2026-66078 is fixed in rabbitmq-server on 1 platform by DEBIAN-CVE-2026-66078 (version 4.3.0-2), released September 26, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-66078
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0043
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rabbitmq-server Debian 14 | 4.3.0-2 | [DEBIAN-CVE-2026-66078](https://patchblox.com/security/data/fix/linux/debian-cve-2026-66078.md) | Sep 26, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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