{"id":"CVE-2026-16100","title":"A flaw was found in the user-event metrics recording of Keycloak","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-s…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-770","CWE-770"],"vendor":"redhat","product":"build_of_keycloak","affected":["build_of_keycloak >= 26.6, < 26.6.5"],"patched":["build_of_keycloak 26.6.5"],"published":"2026-08-05","updated":"2026-08-31","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-16100","references":[{"url":"https://access.redhat.com/errata/RHSA-2026:50848","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:50849","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2026-16100","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2501730","label":"secalert@redhat.com"}],"tags":["nvd"],"epss":0.00404,"epssPercentile":0.34364,"ingestedAt":"2026-08-31T13:08:32.850Z","slug":"CVE-2026-16100","body":"## Overview\n\nA 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.\n\n## Affected\n\n- `build_of_keycloak >= 26.6, < 26.6.5`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `build_of_keycloak 26.6.5`","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}