CVE-2026-16100
Keycloak-services: keycloak-services: unbounded metric cardinality in user event metrics via request-controlled error text
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
A flaw was found in the user-event metrics recording of Keycloak. When metrics are enabled, the system records raw error messages from failed account operations as Prometheus metric labels. Because these error messages can include user-supplied input like nonexistent client IDs, an authenticated user can create a massive number of unique metric entries, eventually exhausting system memory and causing the service to crash or become unavailable.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- rhbk/keycloak-operator-bundle
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- rhbk/keycloak-rhel9-operator
Version range not reported
- keycloak-services
Version range not reported
- rhbk-keycloak-rhel9/rhbk-keycloak-rhel9
Version range not reported
- rhbk-openshift-rhel9/rhbk-openshift-rhel9
Version range not reported
- keycloak-services
Version range not reported
- keycloak-services
Version range not reported
- keycloak-services
Version range not reported