What is CVE-2026-11540?

CVE-2026-11540 is a medium-severity vulnerability in IBM Websphere Application Server, classified under Incorrect Authorization. CVSS score: 5.3/10. Published 2026-09-18.

How severe is CVE-2026-11540?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Auth bypass in IBM Websphere Application Server

CVE-2026-11540

IBM WebSphere Application Server 9.0 and 8.5 could allow a remote attacker to obtain sensitive information about the file system through the FileTransfer servlet.

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Ibm Websphere Application Server — versions 8.5, 9.0

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

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

Frequently asked questions

What is CVE-2026-11540?: CVE-2026-11540 is a medium-severity vulnerability in IBM Websphere Application Server, classified under Incorrect Authorization. CVSS score: 5.3/10. Published 2026-09-18.
How severe is CVE-2026-11540?: Medium severity. CVSS v3 base score is 5.3 out of 10.