Vulnerability in IBM Websphere Application Server

CVE-2026-8400

IBM WebSphere Application Server 8.5, and 9.0 and IBM WebSphere Application Server - Liberty Continuous delivery has a flaw in the ORB component in IBM SDK, Java Technology Edition, may allow a malicious IIOP server to induce loading and instantation of arbitrary classes.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (41.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-8400: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-8400?
CVE-2026-8400 is a high-severity vulnerability in IBM Websphere Application Server, classified under Use of Externally-Controlled Input to Select Classes or Code (Unsafe Reflection). CVSS score: 8.1/10. Published 2026-08-05.
How severe is CVE-2026-8400?
High severity. CVSS v3 base score is 8.1 out of 10.