What is CVE-2021-20391?

CVE-2021-20391 is a low-severity vulnerability in IBM Qradar Siem, classified under CWE-922. CVSS score: 3.3/10. Published 2021-05-14.

How severe is CVE-2021-20391?

Low severity. CVSS v3 base score is 3.3 out of 10.

Vulnerability in IBM Qradar Siem

CVE-2021-20391

IBM QRadar User Behavior Analytics 1.0.0 through 4.1.0 allows web pages to be stored locally which can be read by another user on the system. IBM X-Force ID: 195999.

Published 2021-05-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (14.6th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.6% 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: 0.002 · change: 0.000

Affected products

IBM Qradar Siem — versions 1.0.0, 4.1.1
IBM Qradar User Behavior Analytics

Weakness classification (CWE)

CWE-922

References

www.ibm.com/support/pages/node/6453103 (Vendor Advisory)
exchange.xforce.ibmcloud.com/vulnerabilities/195999 (VDB Entry, vdb-entry, Vendor Advisory)

Frequently asked questions

What is CVE-2021-20391?: CVE-2021-20391 is a low-severity vulnerability in IBM Qradar Siem, classified under CWE-922. CVSS score: 3.3/10. Published 2021-05-14.
How severe is CVE-2021-20391?: Low severity. CVSS v3 base score is 3.3 out of 10.