XSS in Red Hat Build Of Keycloak

CVE-2026-37980

A flaw was found in Keycloak, specifically in the organization selection login page. A remote attacker with `manage-realm` or `manage-organizations` administrative privileges can exploit a Stored Cross-Site Scripting (XSS) vulnerability. This flaw occurs because the `organization.alias` is placed into an inline JavaScript `onclick` handler, allowing a crafted JavaScript payload to execute in a user's browser when they view the login page. Successful exploitation enables arbitrary JavaScript execution, potentially leading to session theft, unauthorized account actions, or further attacks against users of the affected realm.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (29.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-37980: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-37980?
CVE-2026-37980 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Cross-site Scripting. CVSS score: 6.9/10. Published 2026-04-14.
How severe is CVE-2026-37980?
Medium severity. CVSS v3 base score is 6.9 out of 10.