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OpenAdvisories
Medium · 5.3 CVE-2026-67418 EUVD-2026-101419

RabbitMQ MQTT 5: inapplicable PUBLISH property disconnects matching subscribers

Published Oct 14, 2026 · Updated Oct 14, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
rabbitmq rabbitmq-server >= 3.13.0, < 3.13.19, >= 4.0.0, < 4.0.24, >= 4.1.0, < 4.1.15, >= 4.2.0, < 4.2.10, >= 4.3.0, < 4.3.5 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 rabbitmq-server 4.3.6-1 —
Debian 13 rabbitmq-server No fix yet —
Debian 12 rabbitmq-server No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 rabbitmq-server No fix yet —
Ubuntu 26.04 LTS rabbitmq-server No fix yet —
Ubuntu 24.04 LTS rabbitmq-server No fix yet —
Ubuntu 22.04 LTS rabbitmq-server No fix yet —
Show 3 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 20.04 LTS rabbitmq-server No fix yet —
Ubuntu Pro 18.04 LTS rabbitmq-server No fix yet —
Ubuntu Pro 16.04 LTS rabbitmq-server No fix yet —
ReleasePackageFixed inAdvisory
Red Hat Hardened Images 1 rabbitmq-server4.3 4.3.6-1.1.hum1 RHSA-2026:82703

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 rabbitmq-server 3.13.7-11 —

Advisories 2

References