Keycloak (Micrometer): Schwachstelle ermöglicht Denial of Service
WID-SEC-2026-3614 · first 29.09.2026 · updated 29.09.2026 · CVSS 3,7
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 einen Denial of Service Angriff durchzuführen.
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
- einen Denial of Service Angriff durchzuführen
Am I affected?
Affected according to the BSI:
- Open Source Keycloak
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
According to the BSI there is no update yet. The vendor notices below name interim protective measures, if any.
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)
- GitHub Security Advisory GHSA-5FH4-QP8Q-2WXM vom 2026-09-28 github.com
- Red Hat Customer Portal CVE-2026-101333 vom 2026-09-28 access.redhat.com
CVE: CVE-2026-101333
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.