CVE-2026-14974 Overview
CVE-2026-14974 is an insecure deserialization vulnerability affecting IBM WebSphere Application Server traditional editions 8.5 and 9.0. A remote attacker can send crafted serialized objects to a vulnerable server and trigger arbitrary code execution during the deserialization process. The flaw is classified under CWE-502, Deserialization of Untrusted Data, and requires no authentication or user interaction. IBM has published advisory information through the IBM Support Page.
Critical Impact
Successful exploitation allows unauthenticated remote code execution on the WebSphere host, leading to full compromise of application server confidentiality, integrity, and availability.
Affected Products
- IBM WebSphere Application Server 8.5 traditional
- IBM WebSphere Application Server 9.0 traditional
- Applications and workloads deployed on the above WebSphere versions
Discovery Timeline
- 2026-07-28 - CVE-2026-14974 published to NVD
- 2026-07-30 - Last updated in NVD database
Technical Details for CVE-2026-14974
Vulnerability Analysis
The vulnerability resides in how IBM WebSphere Application Server traditional processes serialized Java objects received from untrusted sources. When the server deserializes attacker-controlled data, gadget chains present in the classpath can be invoked to execute arbitrary code within the JVM process. The issue affects the traditional editions of WebSphere 8.5 and 9.0 and is exploitable over the network without authentication. Attack complexity is elevated because exploitation depends on reaching a deserialization endpoint and constructing a viable gadget chain against the target's classpath. The result is complete compromise of the application server, allowing lateral movement into backend systems, credential theft, and disruption of hosted business applications.
Root Cause
The root cause is unsafe deserialization of untrusted data ([CWE-502]). WebSphere accepts serialized Java objects from remote input paths and instantiates them without validating the object graph or restricting allowed classes. Deserialization triggers readObject, readResolve, and related callback methods on attacker-supplied types, which can chain into runtime execution primitives.
Attack Vector
An unauthenticated remote attacker reaches an exposed WebSphere endpoint that accepts serialized data, such as IIOP, SOAP, or management interfaces. The attacker submits a malicious serialized payload constructed from a known Java deserialization gadget chain compatible with libraries loaded by WebSphere. When the server deserializes the payload, the gadget chain executes operating system commands under the identity of the WebSphere process.
No verified public proof-of-concept code is available. Refer to the IBM Support Page for vendor technical details.
Detection Methods for CVE-2026-14974
Indicators of Compromise
- Unexpected child processes spawned by the WebSphere Java process, such as cmd.exe, powershell.exe, /bin/sh, or bash
- Outbound network connections from the WebSphere JVM to unknown external hosts shortly after inbound IIOP or SOAP traffic
- New or modified JSP, WAR, or class files in WebSphere deployment directories outside of change windows
- Java stack traces in SystemOut.log referencing readObject, InvokerTransformer, or other known gadget classes
Detection Strategies
- Inspect HTTP, IIOP, and JMX traffic for serialized Java object magic bytes (ac ed 00 05) sent to WebSphere ports
- Alert on the WebSphere Java process spawning shell interpreters or scripting hosts, a strong signal of gadget-chain execution
- Correlate authentication-less requests to management endpoints with subsequent process creation events on the host
Monitoring Recommendations
- Enable verbose access logging on WebSphere administrative and IIOP listeners and forward logs to a centralized SIEM
- Baseline normal child-process behavior of the WebSphere JVM and alert on deviations
- Monitor file integrity for installedApps, config, and temp directories under the WebSphere profile root
How to Mitigate CVE-2026-14974
Immediate Actions Required
- Apply the IBM interim fix or fix pack referenced in the IBM Support Page to all WebSphere 8.5 and 9.0 traditional instances
- Restrict network access to WebSphere administrative, IIOP, and SOAP connector ports to trusted management networks only
- Audit deployed applications for exposed endpoints that accept serialized Java objects and disable them where not required
Patch Information
IBM has published remediation guidance and fix availability on the IBM Support Page for CVE-2026-14974. Administrators should identify the exact fix pack or interim fix that matches their WebSphere 8.5 or 9.0 build level and apply it after validating in a non-production environment.
Workarounds
- Place WebSphere behind a reverse proxy or web application firewall that blocks requests containing Java serialization magic bytes on non-management endpoints
- Enforce WebSphere's serialization filtering configuration to allow-list only required classes for deserialization
- Segment WebSphere hosts from sensitive backend systems to limit blast radius if exploitation occurs
# Example: enable JDK serialization filter for WebSphere JVM (illustrative)
# Add to the JVM generic arguments in the WebSphere admin console
-Djdk.serialFilter="!org.apache.commons.collections.functors.*;!org.codehaus.groovy.runtime.*;maxdepth=20;maxrefs=500"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
