PT-2026-53942 · Ibm · Ibm Websphere Extreme Scale

Published

2026-06-30

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Updated

2026-06-30

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CVE-2026-13759

CVSS v3.1

7.5

High

VectorAV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
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

Fix

Deserialization of Untrusted Data

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Weakness Enumeration

Related Identifiers

CVE-2026-13759

Affected Products

Ibm Websphere Extreme Scale