CVE-2026-13759: high-severity vulnerability in IBM WebSphere Extreme Scale
IBM WebSphere eXtreme Scale is affected by Insecure Deserilization
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
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
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
IBM · WebSphere Extreme ScaleRelated CVEs — IBM WebSphere Extreme Scale
In the same product, most dangerous first.
CVE-2026-13773MEDIUMIBM WebSphere eXtreme Scale is affected by server side request forgery when ORB is used as Transport ProtocolEPSS 6.1%CVE-2026-13772HIGHIBM WebSphere eXtreme Scale's OQL is affected by remote code executionEPSS 0.5%CVE-2026-9002MEDIUMIBM WebSphere eXtremes Scale is affected by uncontrolled resource consumption when XDF is enabledEPSS 0.3%