CVE-2026-13759
IBM WebSphere eXtreme Scale is affected by Insecure Deserilization
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 ships three ObjectInputStream subclasses (WsObjectInputStream, ObjectStreamPool$ReusableInputStream, ObjectInputStreamResolver) that install no JEP-290 class filter; when Coherence is on the classpath, multiple RCE gadget chains including RemoteConstructor.readResolve and PriorityQueue/ExtractorComparator are confirmed working, allowing a post-login attacker who can write a session attribute or a LAN-adjacent attacker on the grid replication wire to execute arbitrary code on peer WAS JVMs
| CWE | CWE-502 |
| Vendor | ibm |
| Product | websphere extreme scale |
| Published | Jun 30, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
IBM / WebSphere Extreme Scale
8.6.1.0 ≤ 8.6.1.6