CVE-2026-12550 in IBM
Summary
by MITRE • 11/04/2026
IBM MQ 9.2.0.0 through 9.2.0.44 LTS, 9.3.0.0 through 9.3.0.42 LTS, 9.4.0.0 through 9.4.0.26 LTS, 9.4.0.0 through 9.4.5.1 CD, and 10.0.0.0 through 10.0.0.5 LTS and CD could allow an authenticated attacker to obtain sensitive information or cause a denial of service due to improper validation of message selection parameters.
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Analysis
by VulDB Data Team • 11/04/2026
The vulnerability identified in IBM MQ versions ranging from 9.2.0.0 through 9.4.5.1, as well as the 10.0.0.x LTS and CD releases, represents a significant security flaw rooted in the improper validation of message selection parameters. This defect allows an authenticated attacker to exploit weaknesses within the queue manager's handling of client requests that specify how messages should be selected or filtered. Unlike vulnerabilities that require unauthenticated access, this issue necessitates valid credentials on the IBM MQ system, which limits its initial attack surface but does not diminish its severity for internal threats or compromised accounts. The core technical flaw lies in the application logic responsible for processing message selection criteria, where input validation is insufficient to prevent malformed or maliciously crafted parameters from causing unexpected behavior within the messaging infrastructure.
From a technical perspective, the vulnerability stems from how IBM MQ processes requests that include specific filters or selectors intended to narrow down the set of messages retrieved by an application. When these parameters are not rigorously validated against expected formats and constraints, they can trigger internal errors or logic bypasses. This lack of robust input sanitization means that an attacker who has successfully authenticated to the system can send specially crafted requests designed to exploit this gap. The exploitation vector typically involves sending messages with malformed selection criteria that the server fails to reject appropriately, leading either to information leakage through error responses or service disruption due to resource exhaustion or crashes within the queue manager process.
The operational impact of this vulnerability is twofold, encompassing both confidentiality and availability concerns. On one hand, an attacker may be able to obtain sensitive information by leveraging improper validation to extract data that should remain restricted or hidden from their specific context. This could involve accessing messages intended for other users or retrieving metadata about the queue structure itself. On the other hand, the vulnerability can lead to a denial of service condition. By repeatedly sending malformed selection parameters, an attacker can cause the IBM MQ server processes to become unstable, consume excessive resources, or crash entirely, thereby disrupting message delivery and affecting business continuity for organizations relying on this middleware for critical communications.
This issue aligns with Common Weakness Enumeration (CWE) category CWE-20, which describes Improper Input Validation. The failure to adequately check the integrity and format of user-supplied data before processing it is a classic example of this weakness. Furthermore, in terms of the MITRE ATT&CK framework, this vulnerability facilitates techniques associated with Discovery and Impact phases. An attacker might use this flaw for Information Gathering by probing system responses to extract details about the environment or configuration. Additionally, if exploited to cause crashes or resource exhaustion, it falls under Denial of Service tactics aimed at impacting Availability. The authenticated nature of the attack also relates to Initial Access vectors where valid credentials are already present but abused for further exploitation rather than initial entry.
Mitigation strategies primarily involve applying the vendor-provided patches and updates released by IBM to address this specific flaw in all affected versions. Organizations running any version from 9.2.0.0 through 10.0.0.5 must prioritize upgrading to a fixed release as soon as possible. In addition to patching, implementing strict network segmentation can help limit the exposure of IBM MQ instances to only those hosts and users that absolutely require access. Enforcing strong authentication policies using multi-factor authentication where applicable reduces the risk of credential compromise leading to exploitation. Monitoring logs for unusual patterns in message selection requests or repeated connection attempts from single sources can also aid in early detection of potential exploitation activities before significant damage occurs.