Keycloak: Arbitrary code execution via Stored Cross-Site Scripting (XSS) in organization selection login page

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.9 · CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N

EPSS

• CVE-2026-37980: 0.36% estimated exploitation activity in the next 30 days; percentile 29.30 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.

Published by the source

14 Apr 2026, 15:30 UTC

Last modified by the source

22 Oct 2026, 21:33 UTC

Source last checked

26 Oct 2026, 16:58 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-m32f-8vh9-2hh3

2. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-m32f-8vh9-2hh3

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-37980

Advisory: Keycloak: Arbitrary code execution via Stored Cross-Site Scripting (XSS) in organization selection login page
IDs: CVE-2026-37980, GHSA-m32f-8vh9-2hh3
Record: https://patchnext.com/advisories/cve-2026-37980 (revision 2, source checked 26 Oct 2026, 16:58 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.keycloak:keycloak-services: affected <= 26.5.5

## Suggested inspection (read-only)
- Maven org.keycloak:keycloak-services: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.keycloak:keycloak-services.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-m32f-8vh9-2hh3 (GitHub-reviewed advisory GHSA-m32f-8vh9-2hh3 lists affected ranges: Maven org.keycloak:keycloak-services >=0 <=26.5.5)

Commands are suggestions: review each one before running it.