CVE-2026-17004 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 an infinite loop.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 08/13/2026
This vulnerability affects IBM i operating systems version 7.6, 7.5, 7.4, and 7.3, presenting a significant security risk that could be exploited by remote attackers to disrupt system availability. The flaw manifests as an infinite loop condition that can be triggered through specific network requests or input processing sequences, leading to complete system unresponsiveness and denial of service for legitimate users. The vulnerability stems from inadequate input validation and control flow management within the system's network processing components, where malformed or specially crafted data packets can cause the system to enter an endless processing cycle that consumes all available CPU resources.
The technical implementation of this vulnerability involves a critical flaw in the operating system's request handling mechanisms where certain protocol parsing functions fail to properly validate input boundaries or termination conditions. When an attacker sends specifically formatted network traffic or data inputs, the system's processing logic enters an infinite loop that prevents normal operation and can only be resolved through manual system reboot or power cycle. This type of vulnerability is classified under CWE-835, which addresses infinite loops or infinite recursion in software implementations where proper exit conditions are not properly enforced.
From an operational impact perspective, this vulnerability represents a severe threat to business continuity and system availability, particularly for organizations relying on IBM i systems for critical business operations. The remote exploitation capability means that attackers do not need physical access or local privileges to cause disruption, making the attack surface extremely wide and potentially affecting multiple systems simultaneously. Organizations using these older operating system versions face significant risk of service interruption during attack windows, with potential cascading effects on downstream applications and services that depend on the affected systems.
The vulnerability aligns with several ATT&CK framework techniques including T1499.004 for Network Denial of Service and T1566.002 for Spearphishing via Web Links, as attackers can leverage network-based exploitation methods to trigger the infinite loop condition through web or network interfaces. System administrators should prioritize immediate patching of affected systems and implement network segmentation controls to limit potential attack vectors. Additional mitigations include implementing rate limiting on network connections, deploying intrusion detection systems to monitor for suspicious traffic patterns, and establishing robust monitoring procedures to detect early signs of system resource exhaustion that could indicate exploitation attempts.
Security teams should conduct comprehensive vulnerability assessments across all IBM i installations to identify systems running the affected versions, while also reviewing system logs for evidence of attempted exploitation or anomalous processing behavior. The remediation process requires careful planning due to potential compatibility issues with patches and the need for thorough testing in production environments before deployment. Organizations should also consider implementing redundant systems and backup procedures to maintain operational continuity during patching operations and to provide alternative service delivery mechanisms if primary systems become unavailable due to this vulnerability.