{"id":"CVE-2026-16100","aliases":["BIT-keycloak-2026-16100","EUVD-2026-53384","GHSA-xj3w-m54w-h7p9"],"status":"published","title":"Keycloak-services: keycloak-services: unbounded metric cardinality in user event metrics via request-controlled error text","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.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00552,"percentile":0.46394,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-770"],"published":"2026-08-05T13:50:57Z","modified":"2026-09-08T08:48:06Z","fixes":[{"ecosystem":"Bitnami","package":"keycloak","fixed_in":["26.6.5"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"keycloak","ranges":[{"type":"SEMVER","events":[{"introduced":"26.6.0"},{"fixed":"26.6.5"}]}]}],"products":[{"vendor":"red hat","product":"red hat build of keycloak 26.6"},{"vendor":"red hat","product":"red hat build of keycloak 26.6.5"},{"vendor":"red hat","product":"red hat data grid 8"},{"vendor":"red hat","product":"red hat jboss enterprise application platform expansion pack"},{"vendor":"red hat","product":"red hat single sign-on 7"},{"vendor":"redhat","product":"build_of_keycloak"}],"references":[{"url":"https://access.redhat.com/errata/RHSA-2026:50848","tags":["vendor-advisory","x_refsource_REDHAT","Vendor Advisory","advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2026:50849","tags":["vendor-advisory","x_refsource_REDHAT","Vendor Advisory","advisory"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-16100","tags":["vdb-entry","x_refsource_REDHAT","Vendor Advisory","advisory"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2501730","tags":["issue-tracking","x_refsource_REDHAT","Issue Tracking","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-16100","tags":["web"]},{"url":"https://github.com/advisories/GHSA-xj3w-m54w-h7p9"}],"sources":{"cve":[{"id":"CVE-2026-16100","title":"Keycloak-services: keycloak-services: unbounded metric cardinality in user event metrics via request-controlled error text","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.","status":"published","published":"2026-08-05T13:50:57.057Z","modified":"2026-08-31T15:01:16.067Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-770","CWE-770"],"updated_at":"2026-11-02T14:20:10.870108Z"}],"euvd":[{"id":"EUVD-2026-53384","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.","status":"published","published":"2026-08-05T13:50:57Z","modified":"2026-08-31T15:01:16Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T18:01:21.100116Z"}],"ghsa":[{"id":"GHSA-xj3w-m54w-h7p9","title":"A flaw was found in the user-event metrics recording of Keycloak. When metrics are enabled, the...","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.","status":"published","published":"2026-08-05T15:32:22Z","modified":"2026-08-05T18:31:35Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:10:07.328501Z"}],"nvd":[{"id":"CVE-2026-16100","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.","status":"published","published":"2026-08-05T15:16:37.573Z","modified":"2026-08-31T12:17:54.79Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:12:35.031043Z"}],"osv":[{"id":"BIT-keycloak-2026-16100","title":"Keycloak-services: keycloak-services: unbounded metric cardinality in user event metrics via request-controlled error text","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.","status":"published","published":"2026-08-25T11:41:46.325Z","modified":"2026-09-08T08:48:06.65629883Z","updated_at":"2026-11-02T15:28:32.162822Z"}]}}