# CVE-2026-67219: RabbitMQ consistent-hash exchange memory exhaustion via unbounded weight

Source: https://junglewise.ai/threats/cve-2026-67219-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-2026-67219 · Severity: info · Published 2026-09-23

RabbitMQ is a messaging broker used to route and buffer data between applications. A user with write access to a consistent-hash exchange can create bindings with arbitrarily large weight values that force the broker to allocate massive amounts of memory. A single malicious binding can consume hundreds of megabytes per cluster node and survive restarts, potentially causing service degradation or denial of service.

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

## Quick answers

**Is CVE-2026-67219 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-67219 being exploited in the wild.

**How severe is CVE-2026-67219?** Informational severity, published 23 September 2026.

**Which products and versions are affected?** VMware RabbitMQ 3.13.0 to 3.13.14, 4.0.0 to 4.0.19, 4.1.0 to 4.1.10, 4.2.0 to 4.2.5.

**Is there a fix for CVE-2026-67219?** A patch was published on 2026-04-23: Fixed in RabbitMQ 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-67219 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-67219?** 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 add_binding/3 function in RabbitMQ's consistent-hash exchange plugin parses the routing key as an integer weight N and uses lists:seq(NextN0, NextN0 + N - 1) to allocate a list, but validate_binding/2 only enforces N >= 1 with no upper bound. An authenticated attacker with write permission on a consistent-hash exchange and read access to a queue can supply an extremely large N value; this list is persisted to Khepri and replicated cluster-wide, consuming ~800 MB per node for a weight of 100,000,000 and persisting across restarts.

## Affected products

- VMware RabbitMQ 3.13.0 to 3.13.14, 4.0.0 to 4.0.19, 4.1.0 to 4.1.10, 4.2.0 to 4.2.5

## Timeline

- 2026-09-23: disclosed: CVE-2026-67219 published
- 2026-04-23: patched: Fixed in RabbitMQ 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0

## 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/v4.3.0](https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0)

## 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)