What is CVE-2026-16189?

CVE-2026-16189 is a medium-severity vulnerability in IBM Websphere Application Server, classified under Improper Output Neutralization for Logs. CVSS score: 4.8/10. Published 2026-09-14.

How severe is CVE-2026-16189?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Vulnerability in IBM Websphere Application Server

CVE-2026-16189

IBM WebSphere Application Server 9.0, and 8.5 could allow a remote attacker to inject forged log entries into the server's administrative log.

Published 2026-09-14 · last modified 2026-09-16.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (20.4th percentile), scored 2026-10-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

IBM Websphere Application Server — versions 8.5, 9.0

Weakness classification (CWE)

CWE-117 — Improper Output Neutralization for Logs

References

www.ibm.com/support/pages/node/7286610 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-16189?: CVE-2026-16189 is a medium-severity vulnerability in IBM Websphere Application Server, classified under Improper Output Neutralization for Logs. CVSS score: 4.8/10. Published 2026-09-14.
How severe is CVE-2026-16189?: Medium severity. CVSS v3 base score is 4.8 out of 10.