VMware RabbitMQ up to 4.3.4 MQTT Parser rabbit_mqtt_packet.erl serialise_prop/2 input validation

Summaryinfo

A vulnerability was found in VMware RabbitMQ up to 3.13.18/4.0.23/4.1.14/4.2.9/4.3.4. It has been classified as problematic. This affects the function serialise_prop/2 of the file deps/rabbitmq_mqtt/src/rabbit_mqtt_packet.erl of the component MQTT Parser. The manipulation leads to input validation. This vulnerability is documented as CVE-2026-67418. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in VMware RabbitMQ up to 3.13.18/4.0.23/4.1.14/4.2.9/4.3.4. This issue affects the function serialise_prop/2 of the file deps/rabbitmq_mqtt/src/rabbit_mqtt_packet.erl of the component MQTT Parser. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is availability. The summary by CVE is:

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5, the MQTT 5 parser in deps/rabbitmq_mqtt/src/rabbit_mqtt_packet.erl accepts Request-Problem-Information on PUBLISH packets even though the property is valid only for CONNECT. An authenticated publisher with topic write permission can cause the broker to store and route that inapplicable property to a separately authenticated matching subscriber. When the subscriber path serializes the outbound PUBLISH, serialise_prop/2 has no matching clause, and the uncontained function_clause exception closes the victim MQTT or Web MQTT connection. The publisher connection and broker remain available, and queued replay, retained-message persistence, and broker-wide denial of service were not established. This issue is fixed in versions 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-67418 since 07/29/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/14/2026).

Upgrading to version 3.13.19, 4.0.24, 4.1.15, 4.2.10 or 4.3.5 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• VMware

Name

• RabbitMQ

Version

• 3.13.0
• 3.13.1
• 3.13.2
• 3.13.3
• 3.13.4
• 3.13.5
• 3.13.6
• 3.13.7
• 3.13.8
• 3.13.9
• 3.13.10
• 3.13.11
• 3.13.12
• 3.13.13
• 3.13.14
• 3.13.15
• 3.13.16
• 3.13.17
• 3.13.18
• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3
• 4.0.4
• 4.0.5
• 4.0.6
• 4.0.7
• 4.0.8
• 4.0.9
• 4.0.10
• 4.0.11
• 4.0.12
• 4.0.13
• 4.0.14
• 4.0.15
• 4.0.16
• 4.0.17
• 4.0.18
• 4.0.19
• 4.0.20
• 4.0.21
• 4.0.22
• 4.0.23
• 4.1.0
• 4.1.1
• 4.1.2
• 4.1.3
• 4.1.4
• 4.1.5
• 4.1.6
• 4.1.7
• 4.1.8
• 4.1.9
• 4.1.10
• 4.1.11
• 4.1.12
• 4.1.13
• 4.1.14
• 4.2.0
• 4.2.1
• 4.2.2
• 4.2.3
• 4.2.4
• 4.2.5
• 4.2.6
• 4.2.7
• 4.2.8
• 4.2.9
• 4.3.0
• 4.3.1
• 4.3.2
• 4.3.3
• 4.3.4

License

• commercial

Website

• Vendor: https://www.vmware.com/

CPE 2.3info

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CPE 2.2info

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