# CVE-2026-57216: RabbitMQ: AMQP 1.0, AMQP 0-9-1, Stream Protocol loopback enforcement can lead to remote guest sessions due to listener-address loopback checks

CVE-2026-57216 is fixed in rabbitmq-server on 1 platform, first by DEBIAN-CVE-2026-57216, released July 18, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-57216
- Priority: High
- CVSS: 10.0 (Moderate)
- EPSS: 0.0050
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 10, 2026
- Weakness: Improper Authentication
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-57216

## Description

RabbitMQ is a messaging and streaming broker. Prior to 3.13.15, 4.0.20, 4.1.11, and 4.2.6, AMQP 0-9-1, AMQP 1.0, and Stream Protocol authentication can allow a loopback-restricted user such as guest to connect remotely when traffic is accepted through a trusted PROXY-protocol path and the backend listener is loopback-bound because the loopback check uses the listener-side socket address instead of the real client source. This issue is fixed in versions 3.13.15, 4.0.20, 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-2026-57216](https://patchblox.com/security/data/fix/linux/debian-cve-2026-57216.md) | Jul 18, 2026 |
| Linux | rabbitmq-server opensuse-leap 16.0 | 4.1.5-160000.2.1 | [OPENSUSE-SU-2026:21903-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21903-1.md) | Sep 22, 2026 |
| Linux | rabbitmq-server sles 16.0 | 4.1.5-160000.2.1 | [SUSE-SU-2026:23869-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23869-1.md) | Sep 22, 2026 |

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Data as of 2026-11-09T01:18:40Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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