# CVE-2026-66072: RabbitMQ: Atom table exhaustion via stream `chunk_selector`

CVE-2026-66072 is fixed in rabbitmq-server on 1 platform by DEBIAN-CVE-2026-66072 (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-2026-66072
- Priority: Routine
- CVSS: 6.5 (Moderate)
- EPSS: 0.0047
- 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-2026-66072

## Description

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1, get_chunk_selector/1 calls binary_to_atom on the raw client-supplied <<"chunk_selector">> property from post-auth subscribe and resolve_offset_spec frames, with no whitelist and no existing guard. An authenticated stream client with read access to any stream can crash the broker node. Preconditions include rabbitmq_stream plugin enabled Authenticated stream-protocol user with read access to at least one stream. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, 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-2026-66072](https://patchblox.com/security/data/fix/linux/debian-cve-2026-66072.md) | Sep 25, 2026 |

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Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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