CVE-2026-9002: IBM WebSphere Extreme Scale

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• IBM WebSphere Extreme Scale: from 8.6.1.0, up to and including 8.6.1.6

Published 2026-06-30. Last modified 2026-07-02.