What is CVE-2026-9311?

CVE-2026-9311 is a critical-severity vulnerability in Ibm Websphere Application Server, classified under Code Injection. CVSS score: 9.0/10. Published 2026-06-01.

How severe is CVE-2026-9311?

Critical severity. CVSS v3 base score is 9.0 out of 10.

RCE in Ibm Websphere Application Server

CVE-2026-9311

IBM WebSphere Application Server 9.0, and 8.5 is vulnerable to remote code execution caused by the bypass of security controls.

Vulnerability class: RCE (Remote Code Execution)

EPSS: 0.003 (49.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Ibm Websphere Application Server — versions 9.0, 8.5
Ibm Websphere_application_server

Weakness classification (CWE)

CWE-94 — Code Injection

References

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

Frequently asked questions

What is CVE-2026-9311?: CVE-2026-9311 is a critical-severity vulnerability in Ibm Websphere Application Server, classified under Code Injection. CVSS score: 9.0/10. Published 2026-06-01.
How severe is CVE-2026-9311?: Critical severity. CVSS v3 base score is 9.0 out of 10.