CVE-2026-93886 in IBM
Summary
by MITRE • 10/13/2026
IBM i 7.3, 7.4, 7.5, and 7.6 could allow a remote authenticated attacker to execute arbitrary script code due to improper validation of user-supplied input.
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Analysis
by VulDB Data Team • 10/13/2026
The vulnerability identified in IBM i operating systems versions 7.3 through 7.6 represents a critical security flaw rooted in the insufficient sanitization and validation of data provided by users within an authenticated context. This issue specifically affects components that process external inputs, allowing a remote attacker who has successfully established valid credentials to inject malicious script code into application workflows. The core technical deficiency lies in the failure to properly validate user-supplied input before it is processed or rendered by the system's internal services. When such input contains executable script fragments rather than expected data types, the underlying software interprets these scripts as legitimate commands, leading to unintended execution contexts that bypass standard security controls designed for authenticated users but not necessarily for code injection attacks within specific application layers.
From a technical perspective, this flaw aligns with Common Weakness Enumeration (CWE) categories such as CWE-79, which describes Cross-Site Scripting vulnerabilities where untrusted data is included in web content without proper validation or escaping, and potentially CWE-20 for Improper Input Validation if the issue extends to server-side script execution. The attack vector requires remote network access and valid authentication credentials, placing it within the ATT&CK framework under techniques related to Initial Access via Valid Accounts and Execution through Command and Scripting Interpreter. An attacker leveraging this vulnerability can manipulate the application's behavior by injecting client-side scripts that execute in the context of other users or server-side processes that handle the tainted input. This capability enables a range of malicious activities, including session hijacking, credential theft, defacement of web interfaces, or using the compromised system as a pivot point for further network intrusion.
The operational impact of this vulnerability is significant because it compromises the integrity and confidentiality of data processed by IBM i systems in enterprise environments. Since authentication is required, the scope of potential damage is limited to users with existing access rights; however, authenticated attackers often possess elevated privileges or access to sensitive internal resources that unauthenticated outsiders do not have. By executing arbitrary scripts, an attacker can exfiltrate confidential information stored within the application's session context, manipulate database records through injected commands if server-side execution occurs, or create persistent backdoors by modifying configuration files accessible via script injection. This undermines trust in the system’s ability to enforce security boundaries between different user roles and data sets, potentially leading to regulatory non-compliance for organizations subject to standards like PCI DSS or HIPAA that mandate strict input validation and secure coding practices.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary defense is the application of vendor-provided security updates and patches released by IBM to address this specific flaw in versions 7.3 through 7.6. Organizations should prioritize applying these fixes to all affected systems, particularly those exposed to network traffic or handling sensitive user inputs. In addition to patching, developers and system administrators must implement robust input validation mechanisms that enforce strict type checking, allowlisting expected characters, and encoding output appropriately to prevent script interpretation. Implementing Web Application Firewalls (WAFs) can also provide an additional layer of defense by detecting and blocking common injection patterns before they reach the vulnerable application logic. Regular security audits and code reviews focusing on input handling procedures are essential to ensure that future development cycles adhere to secure coding standards, thereby reducing the attack surface for similar vulnerabilities in IBM i environments.