CVE-2026-11713: IBM WebSphere Liberty Privilege Escalation

CVE-2026-11713 Overview

IBM WebSphere Application Server Liberty contains a privilege escalation vulnerability affecting versions 17.0.0.3 through 26.0.0.9 when the restConnector-2.0 feature is enabled. The issue stems from an authorization flaw [CWE-863] that allows an authenticated attacker with low privileges to perform actions beyond their assigned role. Successful exploitation can compromise confidentiality and integrity of application data accessible through the REST connector interface. The vulnerability requires network access and valid credentials but no user interaction.

Critical Impact
An authenticated low-privilege user can escalate access through the restConnector-2.0 management interface, exposing administrative functions and application data.

Affected Products

IBM WebSphere Application Server Liberty 17.0.0.3 through 26.0.0.9
Deployments with the restConnector-2.0 feature enabled
Environments exposing the Liberty JMX REST connector endpoint

Discovery Timeline

2026-10-13 - CVE CVE-2026-11713 published to NVD
2026-10-13 - Last updated in NVD database

Technical Details for CVE-2026-11713

Vulnerability Analysis

IBM WebSphere Application Server Liberty exposes a Java Management Extensions (JMX) interface through the restConnector-2.0 feature. This feature enables remote management operations over HTTPS, including MBean invocation, configuration inspection, and runtime control. The vulnerability allows an authenticated user to perform operations their role should not permit, which maps to the Common Weakness Enumeration category for incorrect authorization [CWE-863].

An attacker with valid Liberty credentials can send crafted REST requests to the connector endpoint and trigger management actions outside their authorization scope. The scope remains unchanged, meaning the escalation occurs within the Liberty server security context rather than crossing a trust boundary to the host operating system. Availability is not affected, but confidential configuration data and integrity of managed resources are at risk.

Root Cause

The root cause is improper authorization enforcement within the restConnector-2.0 request handling path. Role checks are not consistently applied to privileged management operations, allowing a user holding a lower role to invoke operations reserved for administrators. See the IBM Support Page for IBM's official technical description.

Attack Vector

Exploitation requires network reachability to the Liberty HTTPS management port and valid authentication credentials. The attacker authenticates to the REST connector, then issues JMX operations that bypass the expected role gate. No user interaction is required, and the attack can be fully automated against exposed endpoints.

No verified proof-of-concept code is publicly available. Refer to the IBM Support Page for authoritative technical detail.

Detection Methods for CVE-2026-11713

Indicators of Compromise

Authentication events to the Liberty restConnector-2.0 endpoint from unexpected source addresses or service accounts
JMX MBean invocations recorded in Liberty audit logs that do not match the authenticated user's assigned role
Unusual configuration reads or writes performed through /IBMJMXConnectorREST URIs

Detection Strategies

Enable Liberty audit logging (audit-1.0 feature) and alert on JMX_MBEAN_ACTION events invoked by non-administrator principals
Correlate HTTP access logs for /IBMJMXConnectorREST/* paths against the expected set of management users
Baseline normal REST connector usage and flag deviations in request volume, source IP, or operation type

Monitoring Recommendations

Forward Liberty audit.log, messages.log, and HTTP access logs to a centralized analytics platform for retention and correlation
Monitor firewall and reverse proxy telemetry for direct external access to the Liberty management port
Review role-to-user mappings in server.xml on a scheduled cadence to detect drift

How to Mitigate CVE-2026-11713

Immediate Actions Required

Inventory all Liberty servers and identify instances with the restConnector-2.0 feature enabled
Apply the IBM-provided fix referenced in the IBM Support Page as soon as it is validated in a test environment
Restrict network access to the Liberty management port to trusted administrative subnets only
Review and tighten role assignments in server.xml to enforce least privilege for REST connector users

Patch Information

IBM has published remediation guidance on the IBM Support Page for WebSphere Application Server Liberty versions 17.0.0.3 through 26.0.0.9. Apply the vendor-supplied interim fix or upgrade to a fixed release level per the advisory.

Workarounds

Disable the restConnector-2.0 feature in server.xml if remote JMX management is not required
Place the Liberty management endpoint behind a reverse proxy that enforces source-IP allowlisting and mutual TLS
Rotate credentials for all accounts authorized to use the REST connector after patching

bash

# Disable restConnector-2.0 in Liberty server.xml by removing the feature element
# <featureManager>
#     <feature>restConnector-2.0</feature>  <-- remove this line
# </featureManager>

# Verify the feature is no longer loaded after restart
grep -i "restConnector" ${WLP_USER_DIR}/servers/<serverName>/logs/messages.log