CVE-2026-16100
Keycloak-services: keycloak-services: unbounded metric cardinality in user event metrics via request-controlled error text
- State
- Published
- Severity
- 6.5 Medium
- Published
- Aug 5, 2026
- Updated
- Aug 31, 2026
- Reserved
- Jul 17, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | redhat |
Weaknesses
- CWE-770 Allocation of Resources Without Limits or Throttling
Affected Products
| Product | Versions |
|---|---|
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6.5Red Hat | |
Red Hat build of Keycloak 26.6.5Red Hat | |
Red Hat build of Keycloak 26.6.5Red Hat | |
Red Hat Data Grid 8Red Hat | |
Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat | |
Red Hat Single Sign-On 7Red Hat |
References
- RHSA-2026:50848vendor-advisory
- RHSA-2026:50849vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-16100vdb-entry
- RHBZ#2501730issue-tracking
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