# CVE-2026-67228: RabbitMQ: Atom exhaustion: to_atom on runtime-parameter component

CVE-2026-67228 is fixed in rabbitmq-server on 1 platform by DEBIAN-CVE-2026-67228 (version 4.3.2-1), released September 25, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-67228
- Priority: Routine
- CVSS: 4.9 (Moderate)
- EPSS: 0.0032
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 23, 2026
- Weakness: Uncontrolled Resource Consumption
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-67228

## Description

RabbitMQ is a messaging and streaming broker. Prior to versions 4.2.7 and 4.3.1, The runtime-parameters lookup path coerces the URL :component segment to an atom with rabbit_data_coercion:to_atom/1 in lookup_component/1 (deps/rabbit/src/rabbit_runtime_parameters.erl), creating a new atom for any previously unseen value. A safe helper, rabbit_registry:binary_to_type/1, which uses binary_to_existing_atom with a catch, already exists but is not used at this call site. lookup_component/1 calls rabbit_data_coercion:to_atom(Component) on the :component segment of the request URL, converting an attacker-supplied string into a new atom. Because the Erlang atom table is bounded and atoms are never garbage collected, an authorized policymaker issuing roughly one million requests with distinct component values can exhaust the atom table and crash the node, resulting in a denial of service. Preconditions include Exploitation requires policymaker privileges and roughly one million requests.. This issue is fixed in versions 4.2.7 and 4.3.1.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rabbitmq-server Debian 14 | 4.3.2-1 | [DEBIAN-CVE-2026-67228](https://patchblox.com/security/data/fix/linux/debian-cve-2026-67228.md) | Sep 25, 2026 |

---

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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.