{"id":"CVE-2026-9801","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-9801","summary":"Keycloak Vulnerable to Improper Validation of Specified Quantity in Input","details":"A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or an attacker compromising an upstream LDAP server, could exploit this vulnerability. By sending a malformed LDAP password policy response during a password authentication request, the attacker can trigger an OutOfMemoryError. This causes the Keycloak Java Virtual Machine (JVM) to terminate, leading to a denial of service (DoS) for all realms on the affected node.","published":"2026-05-28T06:31:10Z","modified":"2026-07-01T21:45:22.511343435Z","cvss":{"score":4.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00477,"percentile":0.39042,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-ldap-federation","fixedVersion":"26.6.3"}],"fix":{"url":"https://github.com/keycloak/keycloak/pull/49514","label":"keycloak/keycloak#49514"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9801"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/issues/49434"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/pull/49514"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/commit/2c4fe42235ba8c265b1da3a30541a270d5bd8c39"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:25097"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:25098"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:30049"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:30050"},{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2026-9801"},{"type":"WEB","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2482473"},{"type":"PACKAGE","url":"https://github.com/keycloak/keycloak"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-01T21:45:22.511343435Z"}}