What is CVE-2021-20392?

CVE-2021-20392 is a medium-severity vulnerability in IBM Qradar Siem, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-05-14.

How severe is CVE-2021-20392?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in IBM Qradar Siem

CVE-2021-20392

IBM QRadar User Behavior Analytics 1.0.0 through 4.0.1 is vulnerable to cross-site scripting. This vulnerability allows users to embed arbitrary JavaScript code in the Web UI thus altering the intended functionality potentially leading to credentials disclosure within a trusted session.

Vulnerability class: XSS (Cross-Site Scripting)

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

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (49.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

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

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.ibm.com/support/pages/node/6453105 (Vendor Advisory)
exchange.xforce.ibmcloud.com/vulnerabilities/196000 (VDB Entry, vdb-entry, Vendor Advisory)

Frequently asked questions

What is CVE-2021-20392?: CVE-2021-20392 is a medium-severity vulnerability in IBM Qradar Siem, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-05-14.
How severe is CVE-2021-20392?: Medium severity. CVSS v3 base score is 6.1 out of 10.