CVE-2026-11378 in IBM
Summary
by MITRE • 09/18/2026
IBM MQ could allow an authenticated attacker to cause a denial of service or potentially execute arbitrary code due to an integer overflow in distribution list processing.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified within IBM Message Queue, commonly referred to as IBM MQ, represents a critical security flaw rooted in improper handling of numerical values during the processing of distribution lists. This specific issue is classified under CWE-190, which denotes an integer overflow or wraparound condition. In this context, the defect occurs when the application processes data structures associated with message routing and distribution mechanisms. An authenticated attacker who has established a valid connection to the IBM MQ server can exploit this weakness by crafting specially formatted requests that trigger an arithmetic error during list processing operations. The core technical flaw lies in the failure of the software to properly validate or bound-check integer values before performing calculations, leading to memory corruption when the resulting value exceeds the allocated buffer size or wraps around to a negative number.
From a technical perspective, this integer overflow allows for heap-based buffer overflows or stack-based corruptions depending on how the distribution list data is managed in memory. When an attacker supplies input that causes the calculated index or length to wrap around, it can lead to writing beyond the bounds of allocated memory regions. This corruption disrupts the internal state of the IBM MQ service and provides a pathway for arbitrary code execution if the attacker can control the content written into the overwritten memory locations. Alternatively, even without successful exploitation for remote code execution, the instability caused by such memory violations typically results in immediate process crashes or hangs, thereby facilitating a denial of service attack against the messaging infrastructure.
The operational impact of this vulnerability is severe due to its potential to compromise both confidentiality and availability within enterprise environments that rely on IBM MQ for asynchronous communication between distributed applications. If an attacker successfully exploits the code execution aspect, they could gain control over the underlying operating system with the privileges of the user account running the IBM MQ service. This level of access allows for further lateral movement, data exfiltration, or installation of persistent backdoors. In scenarios where only denial of service is achieved, critical business processes dependent on reliable message queuing are disrupted, leading to significant downtime and potential financial loss depending on the industry sector involved.
Mitigation strategies must focus on both immediate remediation and long-term architectural hardening. The primary defense is applying the latest security patches provided by IBM that address this specific integer overflow in distribution list processing. Organizations should ensure their patch management processes are up to date with vendor releases for IBM MQ components. Additionally, network segmentation plays a crucial role in limiting exposure; since exploitation requires authentication, restricting access to IBM MQ ports to only trusted IP addresses and enforcing strong credential policies reduces the attack surface. Implementing strict input validation at application boundaries that interact with MQ can also help prevent malformed data from reaching vulnerable internal handlers.
This vulnerability aligns with MITRE ATT&CK techniques related to initial compromise and privilege escalation, specifically those involving exploitation of software vulnerabilities for remote code execution or denial of service. Security teams should monitor logs for unusual authentication patterns followed by rapid connection terminations or error spikes indicative of crashes. Regular penetration testing focused on message queue interfaces can help identify similar implementation flaws before they are exploited in the wild. Maintaining a robust vulnerability management program that prioritizes fixes for authenticated remote code execution risks is essential to preserving the integrity and availability of enterprise messaging systems.