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

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Advisories

No advisories yet.

Fixes

Solution

We recommend customer to enable encryption. Please follow the link to enable encryption. https://www.ibm.com/docs/en/wxs/latest?topic=sydgies-securing-data-that-flows-between-extreme-scale-clients-servers-ssl-encryption. For extra security customer can enable JEP 290 global JVM deserialization filter (-Djdk.serialFilter) while starting catalog and container servers.JEP 290 is available from 8.0.8.5 onwards.


Workaround

No workaround given by the vendor.

History

Tue, 30 Jun 2026 19:30:00 +0000

Type Values Removed Values Added
Description 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
Title IBM WebSphere eXtreme Scale is affected by Insecure Deserilization
First Time appeared Ibm
Ibm websphere Extreme Scale
Weaknesses CWE-502
CPEs cpe:2.3:a:ibm:websphere_extreme_scale:8.6.1.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:websphere_extreme_scale:8.6.1.6:*:*:*:*:*:*:*
Vendors & Products Ibm
Ibm websphere Extreme Scale
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: ibm

Published:

Updated: 2026-06-30T19:24:03.665Z

Reserved: 2026-06-29T18:10:36.156Z

Link: CVE-2026-13759

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-30T20:30:04Z

Weaknesses