CVE-2026-15280 Overview
CVE-2026-15280 is a path-segment injection vulnerability affecting IBM WebSphere Application Server Liberty versions 17.0.0.3 through 26.0.0.8 ND Collective Controller. The flaw resides in the collective routing mechanism and is classified as an improper limitation of a pathname to a restricted directory [CWE-22]. Remote attackers can exploit this vulnerability over the network without authentication or user interaction. Successful exploitation compromises confidentiality by exposing restricted resources routed through the Collective Controller. IBM has published a support advisory documenting the affected releases and the corrective fix.
Critical Impact
Unauthenticated network attackers can inject malicious path segments into collective routing requests to access sensitive information handled by the WebSphere Liberty ND Collective Controller.
Affected Products
- IBM WebSphere Application Server Liberty 17.0.0.3 through 26.0.0.8
- IBM WebSphere Application Server Liberty ND Collective Controller
- Deployments using collective routing across managed Liberty members
Discovery Timeline
- 2026-07-28 - CVE-2026-15280 published to NVD
- 2026-07-30 - Last updated in NVD database
Technical Details for CVE-2026-15280
Vulnerability Analysis
The vulnerability affects the Collective Controller component in IBM WebSphere Application Server Liberty Network Deployment. The Collective Controller routes administrative and application traffic between Liberty servers joined to a collective. The routing subsystem constructs internal request paths using untrusted input segments. An attacker can craft requests containing malicious path segments that alter the routing target within the collective. This category of flaw maps to [CWE-22], improper limitation of a pathname to a restricted directory. The result is confidentiality loss, since integrity and availability are unaffected according to the CVSS vector. The attack vector is fully remote and requires no privileges or user interaction, which raises the operational risk for internet-exposed controllers.
Root Cause
The root cause is insufficient validation and normalization of path segments processed by the collective routing logic. When user-controlled input flows into path construction without canonicalization, the resulting URI can traverse routing boundaries. Attackers can therefore reach endpoints or resources not intended to be exposed through the Collective Controller.
Attack Vector
Exploitation occurs over the network against the Collective Controller endpoint. An unauthenticated attacker submits an HTTP request that embeds crafted path segments into the collective routing mechanism. The controller processes the manipulated path and returns or exposes data belonging to a different routed resource. No user interaction is required, which enables scripted mass exploitation against exposed controllers.
No verified public proof-of-concept is available at the time of publication. Consult the IBM Support Page for authoritative technical details.
Detection Methods for CVE-2026-15280
Indicators of Compromise
- Inbound HTTP requests to the Collective Controller containing encoded traversal sequences such as %2e%2e, ..%2f, or repeated / separators in routing paths.
- Unexpected access to internal collective member endpoints originating from a single external source.
- Liberty messages.log or http_access.log entries showing routing to member paths that do not match the requested resource.
Detection Strategies
- Inspect HTTP request URIs for path-segment anomalies targeting Collective Controller routes and correlate with authentication state.
- Baseline legitimate collective routing traffic and alert on requests whose normalized path differs from the raw path.
- Deploy web application firewall rules that reject requests containing traversal sequences before they reach the Liberty runtime.
Monitoring Recommendations
- Forward Liberty access, audit, and FFDC logs to a centralized SIEM for retention and correlation.
- Monitor Collective Controller administrative ports for unauthenticated requests from non-management network segments.
- Alert on spikes in 404, 403, or 500 responses from the controller, which can indicate probing.
How to Mitigate CVE-2026-15280
Immediate Actions Required
- Apply the IBM-provided fix documented on the IBM Support Page to all Liberty ND Collective Controllers.
- Inventory every Liberty runtime between 17.0.0.3 and 26.0.0.8 and confirm patch status.
- Restrict Collective Controller endpoints to management networks and block external exposure.
Patch Information
IBM has published remediation guidance and fix availability for affected WebSphere Application Server Liberty releases. Refer to the IBM Support Page for the specific interim fix identifier, applicable versions, and upgrade path. Apply the fix or upgrade to a corrected release across every collective member and controller.
Workarounds
- Place the Collective Controller behind a reverse proxy or WAF that normalizes URIs and rejects traversal sequences before forwarding.
- Enforce network segmentation so only authorized management hosts can reach the Collective Controller ports.
- Enable and review Liberty audit logging to identify probing attempts while patching is scheduled.
# Configuration example: restrict Collective Controller access via host-based firewall
# Allow only the management subnet to reach the controller HTTPS port
iptables -A INPUT -p tcp --dport 9443 -s 10.10.20.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 9443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
