RabbitMQ: AMQP 1.0 symbolic body descriptor prefix collisions bypass validation

Summary

RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.24, 4.1.15, 4.2.10, and 4.3.4, the optimized AMQP 1.0 server_mode parser in deps/amqp10_common/src/amqp10_binary_parser.erl matches the textual prefixes of symbolic data, sequence, and value body descriptors without verifying their encoded symbol lengths. An authenticated AMQP 1.0 publisher with write permission can submit a well-formed unknown descriptor that begins with a registered body descriptor, and RabbitMQ misclassifies and stores the bytes as a standard body section. Strict AMQP 1.0 consumers can terminate while decoding the stored entry. For bodies misclassified as data, AMQP 0-9-1 or other cross-protocol conversion performs full body decoding and can terminate the consumer protocol process, with acknowledgement-required delivery permitting repeated failures. Sequence and value classifications are normally transported as opaque encoded payloads on that conversion path. The broker remains alive, and the issue does not bypass routing or authorization. This issue is fixed in versions 4.0.24, 4.1.15, 4.2.10, and 4.3.4.

Timeline

1. Oct 14, 2026, 4:00 PM UTCCVE published
2. Oct 15, 2026, 6:59 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: no · Technical impact: partial

3. Oct 15, 2026, 7:00 PM UTCRecord last updated

Affected versions

• rabbitmq rabbitmq-server

  From 4.0.0 · fixed in 4.0.24; From 4.1.0 · fixed in 4.1.15; From 4.2.0 · fixed in 4.2.10; From 4.3.0 · fixed in 4.3.4

• rabbitmqBitnami

  From 4.0.0 · fixed in 4.0.24; From 4.1.0 · fixed in 4.1.15; From 4.2.0 · fixed in 4.2.10; From 4.3.0 · fixed in 4.3.4

References 6