Deserialization of Untrusted Data in IBM WebSphere Application Server - CVE-2026-11536

Vulnerability identifier: #VU135125

CSH Severity: Low

CVSS v4: 5.8 [CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H]

CVE-ID: CVE-2026-11536

CWE-ID: CWE-502

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote user to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

IBM WebSphere Application Server
IBM Business Automation Workflow
IBM Tivoli System Automation Application Manager
IBM Security Guardium Key Lifecycle Manager (GKLM)
WebSphere Service Registry and Repository
WebSphere Remote Server
IBM Rational ClearQuest
IBM Tivoli Netcool Configuration Manager
Tivoli Composite Application Manager for Application Diagnostics

Install updates from vendor's website.

IBM WebSphere Application Server - addressed in versions 8.5.5.30, 9.0.5.29

• https://www.ibm.com/support/pages/node/7277544

• Deserialization of untrusted data in IBM WebSphere Application Server
• Multiple vulnerabilities in IBM WebSphere Service Registry and Repository
• Deserialization of untrusted data in IBM WebSphere Remote Server
• Multiple vulnerabilities in IBM Buinses Automation Workflow
• Deserialization of untrusted data in IBM Guardium Key Lifecycle Manager (SKLM/GKLM)
• Deserialization of untrusted data in IBM Tivoli Composite Application Manager for Application Diagnostics
• Multiple vulnerabilities in IBM Tivoli Netcool Configuration Manager
• Deserialization of untrusted data in IBM Tivoli System Automation Application Manager
• Deserialization of untrusted data in IBM Rational ClearQuest