CVE-2026-18142 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 a remote authenticated attacker to cause a denial of service and perform limited memory corruption due to an integer overflow.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
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 initial releases of version 10.0.0.x LTS and CD editions, represents a critical security flaw rooted in improper handling of integer arithmetic within the message queueing middleware. This specific defect is classified under CWE-190, which denotes Integer Overflow or Wraparound, a category of weaknesses where an application performs calculations on integers without verifying that the result fits within the allocated data type limits. In the context of IBM MQ, this flaw manifests when processing certain malformed or specially crafted messages sent by remote authenticated users. The attacker leverages specific input parameters to trigger an arithmetic operation that exceeds the maximum value representable by the integer variable used in memory allocation or buffer management routines. This overflow condition leads to a miscalculation of required memory size, resulting in insufficient buffer allocation relative to the actual data being processed.
From an operational perspective, this vulnerability allows for both denial of service and limited memory corruption effects. The primary impact is often observed as a crash or hang within the IBM MQ queue manager process, effectively disrupting message delivery services for all connected applications relying on that instance. This constitutes a significant availability risk in enterprise environments where continuous messaging infrastructure is critical to business operations. Furthermore, because the integer overflow leads to incorrect memory allocation boundaries, it creates conditions ripe for heap corruption. While the vendor description notes limited memory corruption capabilities, such flaws can potentially be exploited further depending on the specific compiler optimizations and runtime environment configurations. An attacker with valid authentication credentials could theoretically manipulate these corrupted memory states to execute arbitrary code or escalate privileges within the context of the MQ service account, although successful exploitation typically requires precise control over heap layout and additional auxiliary vulnerabilities.
The requirement for remote authenticated access defines the threat model significantly. Unlike unauthenticated attacks that target exposed services directly from the internet, this vulnerability necessitates that an attacker first obtain valid credentials to connect to the IBM MQ server. This constraint limits the attack surface primarily to internal networks or environments where authentication mechanisms have been compromised through phishing, credential stuffing, or other lateral movement techniques. Consequently, while the severity is high due to the potential for service disruption and memory corruption, the practical exploitability depends heavily on the organization's identity management practices and network segmentation strategies. Attackers must navigate past initial access controls before they can attempt to trigger this integer overflow condition within the message processing pipeline.
Mitigation efforts should prioritize immediate patching to the latest fixed versions provided by IBM for each respective product line, ensuring that all affected LTS and CD editions are updated beyond the specified vulnerable ranges. In scenarios where immediate patching is not feasible due to operational constraints or testing requirements, organizations should implement strict network segmentation policies to restrict access to MQ ports exclusively from trusted application servers and administrative workstations. Additionally, deploying intrusion detection systems configured with signatures capable of identifying anomalous message sizes or unusual authentication patterns can provide an additional layer of defense. Regular auditing of user accounts and enforcement of least-privilege principles are essential to reduce the likelihood of credential compromise that could lead to exploitation of this vulnerability. Continuous monitoring for signs of service instability, such as unexpected queue manager restarts or increased error logs related to memory allocation failures, will aid in early detection of potential exploitation attempts.