What is CVE-2026-13759?

CVE-2026-13759 is a high-severity vulnerability in Ibm Websphere Extreme Scale, classified under Deserialization of Untrusted Data. CVSS score: 7.5/10. Published 2026-06-30.

How severe is CVE-2026-13759?

High severity. CVSS v3 base score is 7.5 out of 10.

Deserialization in Ibm Websphere Extreme Scale

CVE-2026-13759

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…

Vulnerability class: Insecure Deserialization

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Ibm Websphere Extreme Scale — versions 8.6.1.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

psirt@us.ibm.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-13759?: CVE-2026-13759 is a high-severity vulnerability in Ibm Websphere Extreme Scale, classified under Deserialization of Untrusted Data. CVSS score: 7.5/10. Published 2026-06-30.
How severe is CVE-2026-13759?: High severity. CVSS v3 base score is 7.5 out of 10.