What is CVE-2019-4304?

CVE-2019-4304 is a medium-severity vulnerability in IBM Websphere Application Server, classified under Session Fixation. CVSS score: 6.3/10. Published 2019-09-30.

How severe is CVE-2019-4304?

Medium severity. CVSS v3 base score is 6.3 out of 10.

Vulnerability in IBM Websphere Application Server

CVE-2019-4304

IBM WebSphere Application Server - Liberty could allow a remote attacker to bypass security restrictions caused by improper session validation. IBM X-Force ID: 160950.

Published 2019-09-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.010 (61.8th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 61.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

IBM Websphere Application Server — versions Liberty
IBM Websphere Application Server

Weakness classification (CWE)

CWE-384 — Session Fixation

References

www.ibm.com/support/pages/node/960171 (Vendor Advisory)
exchange.xforce.ibmcloud.com/vulnerabilities/160950 (VDB Entry, vdb-entry, Vendor Advisory)

Frequently asked questions

What is CVE-2019-4304?: CVE-2019-4304 is a medium-severity vulnerability in IBM Websphere Application Server, classified under Session Fixation. CVSS score: 6.3/10. Published 2019-09-30.
How severe is CVE-2019-4304?: Medium severity. CVSS v3 base score is 6.3 out of 10.