# CVE-2026-67223: RabbitMQ: LDAP DN injection via unescaped substitution

CVE-2026-67223 is fixed in rabbitmq-server on 1 platform by DEBIAN-CVE-2026-67223 (version 4.3.6-1), released October 10, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-67223
- Priority: High
- CVSS: 7.1 (Moderate)
- EPSS: 0.0036
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026
- Weakness: Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-67223

## Description

RabbitMQ is a messaging and streaming broker. The advisory establishes affected 3.13, 4.0, 4.1, 4.2, and 4.3 maintenance lines but contains conflicting first-fixed versions for the 3.13, 4.0, and 4.1 lines. fill/2 substitutes ${username} into user_dn_pattern without RFC 4514 DN escaping, allowing a crafted username to alter the LDAP bind DN and potentially select a different directory entry. Exploitation requires rabbitmq_auth_backend_ldap with a user_dn_pattern containing ${username}, a directory layout in which the injected suffix resolves usefully, and a password valid for the resulting DN. The advisory body identifies 3.13.15, 4.0.20, 4.1.11, 4.2.9, and 4.3.3 as fixed, while structured metadata identifies 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3. No fixed-version assertion is certifiable until a curator resolves this conflict.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rabbitmq-server Debian 14 | 4.3.6-1 | [DEBIAN-CVE-2026-67223](https://patchblox.com/security/data/fix/linux/debian-cve-2026-67223.md) | Oct 10, 2026 |

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Data as of 2026-11-08T13:06:02Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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