What is CVE-2026-11536?

CVE-2026-11536 is a high-severity vulnerability in IBM Websphere Application Server, classified under Deserialization of Untrusted Data. CVSS score: 8.5/10. Published 2026-07-30.

How severe is CVE-2026-11536?

High severity. CVSS v3 base score is 8.5 out of 10.

Deserialization in IBM Websphere Application Server

CVE-2026-11536

IBM WebSphere Application Server 9.0, and 8.5 is affected by a remote code execution vulnerability in the SOAP/JMX connector.

Vulnerability class: Insecure Deserialization

Published 2026-07-30 · last modified 2026-10-23.

CVSS v3 metric

CVSS v3 base score 8.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (47.7th percentile), scored 2026-10-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 47.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

IBM Websphere Application Server — versions 9.0, 8.5
IBM Websphere Application Server

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

www.ibm.com/support/pages/node/7277544 (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-11536?: CVE-2026-11536 is a high-severity vulnerability in IBM Websphere Application Server, classified under Deserialization of Untrusted Data. CVSS score: 8.5/10. Published 2026-07-30.
How severe is CVE-2026-11536?: High severity. CVSS v3 base score is 8.5 out of 10.