{"cve":{"cve_id":"CVE-2023-6563","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.01239,"epss_percentile":0.68604,"epss_as_of":"2026-10-15","description":"An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (> 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the \"consents\" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system.","published_at":"2023-12-14T18:01:26.005000Z","last_modified_at":"2026-09-22T04:17:56.693000Z","cvss_v3_score":7.7,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-770"],"nvd_references":["https://access.redhat.com/errata/RHSA-2023:7854","https://access.redhat.com/errata/RHSA-2023:7855","https://access.redhat.com/errata/RHSA-2023:7856","https://access.redhat.com/errata/RHSA-2023:7857","https://access.redhat.com/errata/RHSA-2023:7858","https://access.redhat.com/security/cve/CVE-2023-6563","https://bugzilla.redhat.com/show_bug.cgi?id=2253308","https://github.com/keycloak/keycloak/issues/13340"],"vuln_status":"Modified","trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-09-23T00:32:41.662445Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack 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Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"C","value_label":"Changed"},{"metric":"C","name":"Confidentiality","value":"N","value_label":"None"},{"metric":"I","name":"Integrity","value":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"keycloak","product_name":"keycloak","version_start":null,"version_start_inclusive":null,"version_end":"21.0.0","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:a:redhat:keycloak:*:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"openshift-container-platform","product_name":"openshift_container_platform","version_start":"4.12","version_start_inclusive":true,"version_end":"4.12","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:a:redhat:openshift_container_platform:4.12:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"openshift-container-platform","product_name":"openshift_container_platform","version_start":"4.11","version_start_inclusive":true,"version_end":"4.11","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:a:redhat:openshift_container_platform:4.11:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"openshift-container-platform-for-ibm-linuxone","product_name":"openshift_container_platform_for_ibm_linuxone","version_start":"4.10","version_start_inclusive":true,"version_end":"4.10","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:a:redhat:openshift_container_platform_for_ibm_linuxone:4.10:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"openshift-container-platform-for-ibm-linuxone","product_name":"openshift_container_platform_for_ibm_linuxone","version_start":"4.9","version_start_inclusive":true,"version_end":"4.9","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:a:redhat:openshift_container_platform_for_ibm_linuxone:4.9:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"openshift-container-platform-for-power","product_name":"openshift_container_platform_for_power","version_start":"4.9","version_start_inclusive":true,"version_end":"4.9","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:a:redhat:openshift_container_platform_for_power:4.9:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"openshift-container-platform-for-power","product_name":"openshift_container_platform_for_power","version_start":"4.10","version_start_inclusive":true,"version_end":"4.10","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:a:redhat:openshift_container_platform_for_power:4.10:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"single-sign-on","product_name":"single_sign-on","version_start":"7.6","version_start_inclusive":true,"version_end":"7.6","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:a:redhat:single_sign-on:7.6:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"single-sign-on","product_name":"single_sign-on","version_start":null,"version_start_inclusive":null,"version_end":null,"version_end_inclusive":null,"cpe23_uri":"cpe:2.3:a:redhat:single_sign-on:-:*:*:*:text-only:*:*:*"}],"exploit_refs":[],"news":[],"references":[{"url":"https://access.redhat.com/errata/RHSA-2023:7854","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2023:7855","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2023:7856","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2023:7857","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2023:7858","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://access.redhat.com/security/cve/CVE-2023-6563","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2253308","source_type":"MISC","tags":[]},{"url":"https://github.com/keycloak/keycloak/issues/13340","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2023-12-14T18:01:26.005000Z","label":"CVE 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