Keycloak (OIDC Dynamic Client Registration): Schwachstelle ermöglicht Manipulation von Dateien
WID-SEC-2026-0152 · first 20.01.2026 · updated 07.04.2026 · CVSS 6,5
What it is about
Keycloak ermöglicht Single Sign-On mit Identity and Access Management für moderne Anwendungen und Dienste. Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Keycloak ausnutzen, um Dateien zu manipulieren und vertrauliche Informationen offenzulegen.
Under what conditions?
Over the network and without logging in. This is the most dangerous combination: attackers can scan reachable devices automatically.
What can happen in the worst case
An attacker could use the vulnerability to
- Dateien zu manipulieren
- vertrauliche Informationen offenzulegen
Am I affected?
Affected according to the BSI:
- Red Hat Enterprise Linux
- Open Source Keycloak OIDC Dynamic Client Registration
- Open Source Keycloak <26.5.6
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- Open Source Keycloak 26.5.6
Is the vulnerability already being exploited?
None of the CVEs is in the CISA catalogue of exploited vulnerabilities. That does not mean there are no attacks, only that none are documented.
Information and sources
- Original BSI advisory (WID)
- Red Hat Bugtracker vom 2026-01-19 bugzilla.redhat.com
- Keycloak 26.5.6 release notes vom 2026-03-19 www.keycloak.org
- Red Hat Security Advisory RHSA-2026:6477 vom 2026-04-02 access.redhat.com
- Red Hat Security Advisory RHSA-2026:6478 vom 2026-04-02 access.redhat.com
CVE: CVE-2026-1180
Source: BSI warning and information service (CERT-Bund); CISA. The assessment of the conditions is my reading of the BSI text; the external pages are in their original language.