CVE-2026-16100
Keycloak-services: keycloak-services: unbounded metric cardinality in user event metrics via request-controlled error text
MEDIUM 6.5
At a glance
- Source
- NVD
- EPSS
- EPSS 0.55 % · percentile 46 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Modified
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.
Weaknesses (CWE)
- CWE-770 — Allocation of Resources Without Limits or Throttling
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | redhat |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · secalert@redhat.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-53384
- GCVE · GCVE-0-2026-16100
CERT-FR advisories
- CERTFR-2026-AVI-0976 — Multiples vulnérabilités dans KeyCloak · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*≥ 26.6 < 26.6.5
Affected products
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |