# CVE-2026-67419: RabbitMQ: Consecutive topic wildcards cause combinatorial routing work

CVE-2026-67419 is fixed in rabbitmq-server on 1 platform by DEBIAN-CVE-2026-67419 (version 4.3.6-1), released October 10, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-67419
- Priority: Routine
- CVSS: 6.5 (Important)
- EPSS: 0.0037
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026
- Weakness: Inefficient Algorithmic Complexity
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-67419

## Description

RabbitMQ is a messaging and streaming broker. Prior to 4.3.5, an authenticated user who can bind a queue to a topic exchange and publish to it can use consecutive # segments in a binding key to make both topic matchers revisit the same trie-node and routing-key-suffix states without memoization. The matcher materializes duplicate destinations before deduplication, causing combinatorial CPU work and memory pressure that can disrupt routing for all tenants. This vulnerability is fixed in 4.3.5.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rabbitmq-server Debian 14 | 4.3.6-1 | [DEBIAN-CVE-2026-67419](https://patchblox.com/security/data/fix/linux/debian-cve-2026-67419.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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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