# CVE-2026-66078: RabbitMQ protected tag bypass in bulk-delete endpoint

Source: https://junglewise.ai/threats/cve-2026-66078-rabbitmq-is-a-messaging-and-streaming-broker-from-3-13-0-until-3  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-25. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-66078 · Severity: info · Published 2026-09-25

RabbitMQ is a message broker used to route and queue messages between applications. An administrator can delete protected service accounts that are supposed to be safeguarded, by using the bulk-delete API endpoint instead of the single-delete endpoint. This bypasses an intentional security control, allowing unauthorized deletion of critical service accounts.

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

## Quick answers

**Is CVE-2026-66078 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-66078 being exploited in the wild.

**How severe is CVE-2026-66078?** Informational severity, published 25 September 2026.

**Which products and versions are affected?** VMware RabbitMQ 3.13.0 to 3.13.14, 4.0.x before 4.0.20, 4.1.x before 4.1.11, 4.2.x before 4.2.6.

**Is there a fix for CVE-2026-66078?** A patch was published on 2026-09-25: Fixed in 3.13.15, 4.0.20, 4.1.11, 4.2.6 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-66078 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-66078?** 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 vulnerability is an authorization bypass in the bulk-delete user endpoint (/api/users/bulk-delete) which fails to check the is_protected_user guard before deleting accounts. While the single-delete endpoint (DELETE /api/users/:name) correctly enforces the protected-tag check via the rabbitmgmtwmuser:deleteresource/2 function, the bulk endpoint bypasses this by calling rabbitauthbackendinternal:deleteuser/2 directly without the guard. An authenticated administrator can exploit this to silently delete protected-tagged users that should be immutable.

## Affected products

- VMware RabbitMQ 3.13.0 to 3.13.14, 4.0.x before 4.0.20, 4.1.x before 4.1.11, 4.2.x before 4.2.6

## Timeline

- 2026-09-25: disclosed
- 2026-09-25: patched: Fixed in 3.13.15, 4.0.20, 4.1.11, 4.2.6

## References

- [https://github.com/rabbitmq/rabbitmq-server/commit/e5b890a64b42ec1f79a8e9d735512150cf77479c](https://github.com/rabbitmq/rabbitmq-server/commit/e5b890a64b42ec1f79a8e9d735512150cf77479c)
- [https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6](https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6)

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- [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)
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