CVE-2026-57221 in RabbitMQ
Summary
by MITRE • 07/10/2026
RabbitMQ is a messaging and streaming broker. Prior to 3.13.15, 4.0.20, 4.1.11, and 4.2.6, RabbitMQ does not perform authorization checks on passive queue.declare and exchange.declare AMQP 0-9-1 operations, allowing any authenticated user who can connect to a virtual host to enumerate queue and exchange names and read queue message and consumer counts. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.
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Analysis
by VulDB Data Team • 07/10/2026
RabbitMQ serves as a critical messaging infrastructure component in distributed systems, facilitating reliable message queuing and streaming operations across various enterprise applications. The vulnerability under analysis affects multiple versions of the RabbitMQ broker software, specifically those prior to 3.13.15, 4.0.20, 4.1.11, and 4.2.6, creating a significant security gap in access control mechanisms. This flaw represents a serious authorization bypass that undermines the fundamental security model of the messaging system.
The technical flaw manifests in the improper implementation of access control checks during passive declaration operations within the AMQP 0-9-1 protocol. Specifically, when authenticated users establish connections to virtual hosts, they can perform queue.declare and exchange.declare operations in passive mode without proper authorization verification. This behavior allows malicious actors or unauthorized users with valid credentials to enumerate all queues and exchanges within a virtual host, gaining visibility into the messaging infrastructure's internal structure. The vulnerability enables information disclosure through the ability to read queue message counts and consumer statistics, providing attackers with valuable intelligence about system activity and potential targets for further exploitation.
The operational impact of this vulnerability extends beyond simple information disclosure, creating substantial risk to enterprise security postures. Attackers can leverage this weakness to map out messaging topology, identify critical queues and exchanges, and understand system behavior patterns without requiring elevated privileges. This reconnaissance capability aligns with ATT&CK technique T1069.001 for credential access through permission groups and T1592 for reconnaissance using network scanning methods. The vulnerability particularly affects environments where multiple users or applications share virtual hosts, as it allows unauthorized enumeration of resources that should remain hidden from unauthorized access.
The security implications are compounded by the fact that this issue affects core messaging operations fundamental to RabbitMQ's functionality. Passive queue and exchange declarations are commonly used operations within message broker architectures, making this vulnerability particularly dangerous as it operates during normal system behavior rather than requiring special attack vectors. Organizations implementing RabbitMQ in production environments face potential exposure of sensitive operational data including queue names that may reveal business processes, application dependencies, or system architecture details. This vulnerability effectively violates the principle of least privilege by allowing unauthorized access to internal system state information.
The fix implemented in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6 addresses the authorization gap through proper access control enforcement during passive declaration operations. This remediation aligns with CWE-284 which specifically addresses improper access control in software systems. Organizations should prioritize upgrading to these fixed versions as part of their security maintenance procedures, particularly given that the vulnerability affects widely used RabbitMQ releases across multiple version streams. Security teams should also conduct thorough assessments of their RabbitMQ deployments to identify any systems running vulnerable versions and implement appropriate monitoring for potential exploitation attempts.
The vulnerability demonstrates the critical importance of proper access control implementation in distributed messaging systems where unauthorized enumeration can provide attackers with significant operational intelligence. This flaw exemplifies how seemingly innocuous protocol operations can create substantial security risks when access controls are improperly enforced, emphasizing the need for comprehensive security testing of messaging infrastructure components. Organizations should implement regular security assessments of their message broker configurations and ensure that all access control mechanisms operate correctly under various operational scenarios to prevent similar vulnerabilities from emerging in other system components.