CVE-2026-11713 in WebSphere Application Server
Summary
by MITRE • 10/13/2026
IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.9 is affected by a privilege escalation vulnerability with the restConnector-2.0 feature enabled.
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Analysis
by VulDB Data Team • 10/13/2026
The IBM WebSphere Application Server Liberty profile, specifically versions ranging from 17.0.0.3 to 26.0.0.9, contains a critical security flaw within its REST connector functionality when the restConnector-2.0 feature is active. This vulnerability represents a significant privilege escalation risk that allows unauthorized users or attackers with low-level access to gain elevated privileges on the underlying system. The core of this issue lies in how the Liberty runtime handles authentication and authorization checks for administrative operations exposed through the REST API interface. When an attacker interacts with specific endpoints managed by the restConnector-2.0 feature, they can exploit a logic error or insufficient validation mechanism that bypasses standard access control procedures. This flaw effectively allows a user who should only have limited operational rights to execute commands or modify configurations reserved for administrators, thereby compromising the integrity and confidentiality of the application server environment.
From a technical perspective, this vulnerability is classified under CWE-269, which denotes Improper Privilege Management. The root cause typically involves inadequate verification of the caller's identity or role before processing sensitive administrative requests. In many enterprise environments running WebSphere Liberty, the REST connector serves as a primary interface for automation and remote management tools. If an attacker can authenticate with even basic credentials, they may leverage this flaw to escalate their session privileges. This could involve manipulating internal state variables, bypassing security constraints defined in configuration files such as server.xml or bootstrap.properties, or exploiting race conditions during the initialization of administrative services. The absence of strict role-based access control enforcement at critical junctures within the REST API handler code creates an attack surface where privilege boundaries are blurred, allowing lateral movement and deeper system compromise once initial foothold is established.
The operational impact of this vulnerability is severe for organizations relying on WebSphere Liberty for mission-critical applications. Successful exploitation can lead to complete control over the application server instance, enabling attackers to deploy malicious code, exfiltrate sensitive data stored within managed resources, or disrupt service availability by altering runtime configurations. In a cloud-native or containerized deployment scenario, which is common with modern Liberty profiles, this escalation could potentially extend beyond the container boundary if default security contexts are not properly hardened. Attackers might use the elevated privileges to install backdoors, modify logging mechanisms to cover their tracks, or pivot to other systems within the internal network that trust the compromised server's identity. The availability of such a high-severity flaw in widely used enterprise middleware underscores the importance of timely patching and rigorous configuration management practices.
To mitigate this risk, organizations must immediately apply the latest security fixes provided by IBM for their specific version of WebSphere Application Server Liberty. It is crucial to verify that all instances running versions between 17.0.0.3 and 26.0.0.9 are updated to a patched release where these privilege escalation paths have been closed. Beyond patching, administrators should enforce strict network segmentation policies to restrict access to the REST API endpoints only from trusted management networks or authorized automation tools. Implementing multi-factor authentication for administrative interfaces adds an additional layer of defense against credential-based attacks that might precede exploitation of this flaw. Furthermore, adopting a principle of least privilege ensures that service accounts and application users operate with minimal necessary permissions, reducing the blast radius if any vulnerability is successfully exploited. Continuous monitoring using intrusion detection systems configured to detect anomalous administrative activity patterns can also aid in early identification of potential exploitation attempts aligned with ATT&CK techniques related to account manipulation or defense evasion.