Integer Overflow Vulnerability in IBM MQ Request Processing (CVE-2026-11725)

IBM MQ contains a critical integer overflow vulnerability, identified as CVE-2026-11725, affecting its processing of MQINQ requests. This vulnerability allows an authenticated attacker with access to the messaging system to manipulate input parameters during the MQINQ call sequence, causing a buffer or memory handling error. The impact of successful exploitation ranges from an immediate denial of service (DoS), causing the queue manager to crash or hang, to the potential for remote arbitrary code execution under the context of the IBM MQ service account. Given the privileged nature of message queuing middleware in enterprise environments, this flaw represents a significant risk for lateral movement or infrastructure disruption. Organizations utilizing IBM MQ should prioritize identifying the patch status of their queue managers and implementing access controls to restrict the ability of unauthorized or untrusted users to perform administrative or inquiries on the messaging infrastructure.

Impact

Successful exploitation of CVE-2026-11725 can lead to a complete service disruption of the IBM MQ messaging backbone, affecting all downstream applications that rely on the queue manager. In scenarios resulting in arbitrary code execution, an attacker may gain persistence on the underlying server, potentially accessing sensitive business messages or pivoting into the internal network.

Recommendation

Prioritize the identification and patching of all IBM MQ instances. Review IBM security bulletins for the specific version-dependent fixed releases. Audit MQ queue manager access controls to ensure that only authorized service accounts and administrators can invoke MQINQ functions, limiting the potential attack surface.