CVE-2026-17077 in IBM
Summary
by MITRE • 08/13/2026
IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to cause a denial of service due to the use of an uninitialized variable.
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Analysis
by VulDB Data Team • 08/13/2026
This vulnerability affects IBM i operating system versions 7.6, 7.5, 7.4, and 7.3, presenting a remote denial of service risk through the exploitation of uninitialized variables within the system's software components. The flaw manifests when the system processes certain network requests or administrative commands that trigger code paths utilizing memory locations not properly initialized before use. This condition creates opportunities for attackers to craft malicious inputs that cause the targeted system to crash or become unresponsive, effectively rendering critical business applications and services unavailable to legitimate users.
The technical implementation of this vulnerability involves the improper initialization of variables within the IBM i system's kernel or middleware components responsible for handling network communications and system management functions. When an uninitialized variable is accessed, it contains arbitrary data from previous operations in memory, potentially leading to unpredictable behavior including invalid memory access violations, incorrect program flow decisions, or buffer overflows that cause system instability. The vulnerability specifically targets the system's response handling mechanisms where remote inputs are processed without proper validation of variable states before execution.
From an operational perspective, this vulnerability presents significant risk to organizations relying on IBM i systems for mission-critical business operations, particularly in financial services, manufacturing, and government sectors where system availability is paramount. Remote exploitation could result in complete service interruption across the affected system, potentially cascading to dependent applications and services that rely on IBM i infrastructure for data processing and transaction handling. The impact extends beyond simple availability concerns as system crashes may also lead to data integrity issues or require extensive recovery procedures including system restarts and potential data restoration from backups.
The vulnerability aligns with CWE-457, which describes "Use of Uninitialized Variable" in software development practices, and demonstrates how improper memory management can lead to severe security consequences. From an attack framework perspective, this issue maps to ATT&CK technique T1499.004 for network denial of service attacks, where adversaries leverage system weaknesses to disrupt availability. Organizations should implement immediate mitigations including applying official IBM security patches, configuring network firewalls to restrict unnecessary access to IBM i management interfaces, and implementing intrusion detection systems to monitor for suspicious network activity patterns that may indicate exploitation attempts.
The remediation strategy must include comprehensive system updates from IBM to address the uninitialized variable conditions in affected code modules. Security teams should also conduct thorough vulnerability assessments of their IBM i environments to identify similar patterns in custom applications or third-party software components that may be susceptible to the same class of memory management issues. Additional protective measures include implementing strict access controls for system administration interfaces, enabling detailed logging of system events and network communications, and establishing incident response procedures specifically designed to address denial of service incidents targeting IBM i systems. Organizations should also consider deploying network segmentation strategies to limit potential attack vectors and reduce the scope of impact if exploitation occurs within their infrastructure.