CVE-2026-67416: rabbitmq rabbitmq-server Improper Input Validation

Vulnerability summary

CVE-2026-67416 is a medium (CVSS 5.3) Improper Input Validation vulnerability in rabbitmq rabbitmq-server. EPSS estimates a 0.54% chance of exploitation in the next 30 days, higher than 44.3% of scored vulnerabilities.

Timeline

1. 14-10-2026
   PublishedVulnerability first disclosed.
2. 15-10-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-20Improper Input ValidationThe 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.
• CWE-248Uncaught ExceptionAn exception is thrown from a function, but it is not caught.
• CWE-754Improper Check for Unusual or Exceptional ConditionsThe product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.