# CVE-2026-9002: IBM WebSphere Extreme Scale denial of service in XDF decoder

Source: https://junglewise.ai/threats/cve-2026-9002-ibm-websphere-extreme-scale-denial-of-service-in-xdf-decoder  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-30. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2026-9002 · Severity: medium · CVSS 6.5 · Published 2026-06-30

IBM WebSphere Extreme Scale, a high-performance data caching solution, is vulnerable to a denial-of-service attack. An attacker on the same local network can send specially crafted data that causes the application to crash by exhausting its memory or processing capacity. This results in a service outage, preventing legitimate users and applications from accessing cached data.

Technologies: [IBM Websphere Extreme Scale](https://junglewise.ai/threats/technologies/websphere-extreme-scale). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-9002 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9002 being exploited in the wild.

**How severe is CVE-2026-9002?** Medium severity, with a CVSS score of 6.5, published 30 June 2026.

**Which products and versions are affected?** IBM Websphere Extreme Scale 8.6.1.0 - 8.6.1.6.

**Is there a fix for CVE-2026-9002?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-9002 attacked?** It is attacked from the adjacent network, in a software library.

**Am I affected by CVE-2026-9002?** Check whether you run IBM Websphere Extreme Scale at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

IBM WebSphere Extreme Scale (versions 8.6.1.0 through 8.6.1.6) contains an uncontrolled resource consumption vulnerability (CWE-400) within its XDF decoder. The component fails to perform sufficient bounds checking on attacker-controlled length prefixes and deeply nested Protocol Buffers messages. An adjacent attacker can exploit this by sending malicious messages that trigger a StackOverflowError or OutOfMemoryError, leading to a crash of the WebSphere Application Server JVM. IBM has released APAR PH71946 to address this issue; users on 8.6.1.6 should apply the iFix, while those on older versions must first upgrade to 8.6.1.6.

## Affected products

- IBM WebSphere Extreme Scale 8.6.1.0 - 8.6.1.6

## Timeline

- 2026-06-29: advisory: Initial publication by IBM
- 2026-06-30: disclosed: NVD publication date

## References

- [https://www.ibm.com/support/pages/node/7278346](https://www.ibm.com/support/pages/node/7278346)

## Related threats

- [IBM WebSphere Extreme Scale security policy bypass](https://junglewise.ai/threats/cve-2026-101117-ibm-websphere-extreme-scale-8-6-1-0-through-8-6-2-2-could-allow)
- [IBM WebSphere Extreme Scale SSRF in ogclient.jar CORBA stubs](https://junglewise.ai/threats/cve-2026-13773-ibm-websphere-extreme-scale-ssrf-in-ogclient-jar-corba-stubs)
- [IBM WebSphere Extreme Scale unsafe reflection in OQL engine](https://junglewise.ai/threats/cve-2026-13772-ibm-websphere-extreme-scale-unsafe-reflection-in-oql-engine)
- [IBM WebSphere Extreme Scale insecure deserialization](https://junglewise.ai/threats/cve-2026-13759-ibm-websphere-extreme-scale-insecure-deserialization)