IBM WebSphere eXtreme Scale 8.6.1.0

IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 could allow an adjacent attacker to cause a denial of service due to improper validation in the XDF decoder. The application processes deeply nested Protocol Buffers messages and attacker-controlled length prefixes without sufficient bounds checking, which may allow an attacker on the same network to trigger a StackOverflowError or OutOfMemoryError, resulting in a crash of the WebSphere Application Server JVM.

Published: 2026-06-30T19:08:43.309Z
Updated: 2026-06-30T19:30:30.663Z

IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 Approximately 50 generated CORBA stub classes in WebSphere eXtreme Scale's ogclient.jar call ORB.string_to_object() on an attacker-controlled IOR string during Java deserialization, turning any unfiltered ObjectInputStream sink in WAS into outbound IIOP SSRF to an attacker-chosen host; when chained with the IBM ORB's getUserException class-instantiation flaw (WAS-26), this SSRF escalates to remote code execution on the calling JVM.

Published: 2026-06-30T19:20:49.312Z
Updated: 2026-06-30T19:37:59.403Z

IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 's Object Query Language engine resolves attacker-supplied class names via Class.forName() and invokes their constructors with no allow-list at three distinct sinks (SELECT NEW, enum literals, and reflection-based comparators); an authenticated remote attacker who can influence an application-built OQL query string can execute arbitrary constructors on the WAS JVM, and a SELECT DISTINCT variant using planted grid values fires the same gadget post-readObject in a manner that survives JEP-290 serialization filters across grid node boundaries

Published: 2026-06-30T19:21:43.212Z
Updated: 2026-07-03T03:56:12.467Z

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

Published: 2026-06-30T19:24:03.665Z
Updated: 2026-07-03T03:56:10.967Z