# CVE-2026-67231: RabbitMQ trust-store plugin TLS client authentication bypass

Source: https://junglewise.ai/threats/cve-2026-67231-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-2026-67231 · Severity: info · Published 2026-09-23

RabbitMQ is a message broker used to route and deliver messages between applications. The optional trust-store plugin, which validates client certificates, can be bypassed by attackers who know the certificate issuer and serial number of any whitelisted certificate. An attacker with this information can forge a self-signed certificate and authenticate without a valid credential, potentially gaining unauthorized access to the message broker.

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

## Quick answers

**Is CVE-2026-67231 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-67231 being exploited in the wild.

**How severe is CVE-2026-67231?** Informational severity, published 23 September 2026.

**Which products and versions are affected?** VMware RabbitMQ 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, before 4.3.0.

**Is there a fix for CVE-2026-67231?** A patch was published on 2026-04-23: RabbitMQ 4.2.6 and 4.3.0 released with fixes Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-67231 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-67231?** 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 trust-store plugin's verify_fun improperly validates client certificates by comparing only the issuer DN and serial number (extracted directly from the presented certificate) against a whitelist, without verifying the certificate signature, public key, or performing path validation. An attacker can forge a self-signed certificate with a known issuer/serial pair to bypass authentication. The vulnerability requires the trust-store plugin to be enabled and the attacker to know or discover the issuer DN and serial number of a whitelisted certificate, which is non-secret information often exposed via logs or certificate copies.

## Affected products

- VMware RabbitMQ 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, before 4.3.0

## Timeline

- 2026-09-23: disclosed: CVE-2026-67231 published
- 2026-04-23: patched: RabbitMQ 4.2.6 and 4.3.0 released with fixes

## 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)