CVE-2026-13759
HIGH
MEDIUM
Priority: 0.05
BB Relevance:
68/100
Published: 2026-06-30
Modified: 2026-10-25
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
No Interaction
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
Low
UI:
None
S:
Unchanged
C:
High
I:
High
A:
High
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
Weakness Classification (1)
Affected Software (1)
| Vendor | Product | Version |
|---|---|---|
| ibm | websphere_extreme_scale | 8.6.1.0 – 8.6.1.6 |
References & Advisories (1)
Vendor Advisory