CVE-2026-11711 in WebSphere Application Server
Summary
by MITRE • 09/18/2026
IBM WebSphere Application Server 9.0 and 8.5 is affected by a deserialization vulnerability in the Name Service component.
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Analysis
by VulDB Data Team • 09/18/2026
The IBM WebSphere Application Server, specifically versions 9.0 and 8.5, contains a critical security flaw within its Name Service component that stems from improper handling of serialized data during object reconstruction processes. This vulnerability arises because the application server accepts untrusted input for deserialization without performing adequate validation or integrity checks on the incoming data stream. When an attacker crafts maliciously formatted objects containing dangerous payloads, they can exploit this lack of verification to execute arbitrary code within the context of the running Java Virtual Machine. The Name Service component is responsible for managing naming and directory services, which are fundamental to how distributed applications locate resources and communicate with each other in enterprise environments. By targeting this specific module, an attacker gains a direct pathway into the core infrastructure that supports application connectivity and resource resolution.
From a technical perspective, this issue is classified as CWE-502, Deserialization of Untrusted Data. The root cause lies in the use of Java serialization mechanisms where objects are converted into byte streams for storage or transmission and subsequently reconstructed back into active objects upon receipt. If the deserialization process does not strictly validate the class types being instantiated or restrict access to dangerous classes such as those capable of executing system commands, it creates a severe attack surface. The vulnerability allows for remote code execution without requiring prior authentication in certain configurations where the Name Service is exposed to untrusted networks. This means that an adversary can send specially crafted network packets containing serialized malicious objects directly to the affected server ports, triggering the unsafe deserialization routine and leading to full system compromise.
The operational impact of this vulnerability is severe, potentially resulting in complete loss of confidentiality, integrity, and availability for systems relying on IBM WebSphere Application Server. Successful exploitation enables an attacker to execute arbitrary commands with the privileges of the application server process, which often runs with elevated permissions necessary for managing enterprise applications. This can lead to unauthorized access to sensitive business data, modification or deletion of critical configuration files, and the establishment of persistent backdoors within the network infrastructure. Furthermore, because WebSphere is frequently used as a backend for high-value web applications, compromising it may serve as a pivot point for lateral movement into other parts of the corporate intranet, amplifying the scope of the breach significantly beyond the initial target system.
To mitigate this risk, organizations must apply the latest security patches and fix packs provided by IBM that address the deserialization flaws in the Name Service component. It is also recommended to implement network-level controls such as firewalls or intrusion prevention systems to restrict access to WebSphere ports from untrusted networks, ensuring that only authorized clients can communicate with the application server. Additionally, administrators should enforce strict input validation and consider disabling unnecessary services or components if they are not required for specific business operations. Adopting a defense-in-depth strategy by monitoring for anomalous network traffic patterns associated with serialization attacks and keeping all software dependencies up to date will further reduce the likelihood of successful exploitation aligned with techniques described in MITRE ATT&CK under T1059 Command and Scripting Interpreter or T1203 Exploitation for Client Execution.