# CVE-2026-66072: RabbitMQ stream protocol atom injection in chunk_selector

Source: https://junglewise.ai/threats/cve-2026-66072-rabbitmq-is-a-messaging-and-streaming-broker-prior-to-versions-3  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-23. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-66072 · Severity: info · Published 2026-09-23

RabbitMQ is a messaging and streaming broker that organizations use to reliably route messages across systems. An authenticated user with read access to any stream can crash the broker by submitting specially crafted requests, disrupting message delivery and availability. This requires the rabbitmq_stream plugin to be enabled and a valid user account with stream read permissions.

Technologies: [VMware RabbitMQ](https://junglewise.ai/threats/technologies/vmware-rabbitmq). Vendors: [VMware](https://junglewise.ai/threats/vendors/vmware).

## Quick answers

**Is CVE-2026-66072 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-66072 being exploited in the wild.

**How severe is CVE-2026-66072?** Informational severity, published 23 September 2026.

**Which products and versions are affected?** VMware RabbitMQ 3.13.x before 3.13.15, 4.0.x before 4.0.20, 4.1.x before 4.1.11, 4.2.x before 4.2.6, 4.3.x before 4.3.1.

**Is there a fix for CVE-2026-66072?** A patch was published on 2026-04-23: RabbitMQ 4.2.6 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-66072 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-66072?** Check whether you run VMware RabbitMQ at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The get_chunk_selector/1 function in RabbitMQ's stream protocol handler calls binary_to_atom on untrusted client input from the chunk_selector property in post-auth subscribe and resolve_offset_spec frames without validation or whitelisting, allowing arbitrary atom creation. An authenticated stream client can trigger an atom table exhaustion denial of service. The vulnerability is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1.

## Affected products

- VMware RabbitMQ 3.13.x before 3.13.15, 4.0.x before 4.0.20, 4.1.x before 4.1.11, 4.2.x before 4.2.6, 4.3.x before 4.3.1

## Timeline

- 2026-09-23: disclosed
- 2026-04-23: patched: RabbitMQ 4.2.6 released
- 2026-05-20: patched: RabbitMQ 4.3.1 released

## References

- [https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6](https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6)
- [https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1](https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1)

## Related threats

- [RabbitMQ MQTT 5 parser invalid property denial of service](https://junglewise.ai/threats/cve-2026-67418-rabbitmq-is-a-messaging-and-streaming-broker-from-3-13-0-until-3)
- [RabbitMQ AMQP 1.0 parser descriptor validation bypass](https://junglewise.ai/threats/cve-2026-67416-rabbitmq-is-a-messaging-and-streaming-broker-from-4-0-0-until-4-0)
- [RabbitMQ AMQP 1.0 parser memory exhaustion](https://junglewise.ai/threats/cve-2026-67414-rabbitmq-is-a-messaging-and-streaming-broker-from-4-0-0-until-4-0)
- [RabbitMQ Management XSS via queue name in OAuth UI](https://junglewise.ai/threats/cve-2026-67421-rabbitmq-is-a-messaging-and-streaming-broker-from-3-13-0-until-3)
- [RabbitMQ JMS topic exchange denial of service via regex wildcard expansion](https://junglewise.ai/threats/cve-2026-67413-rabbitmq-is-a-messaging-and-streaming-broker-from-4-0-0-until-4-0)