Description
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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Red Hat Red Hat build of Keycloak 26.4
Default version status: affected
26.4.13-1 to < *unaffected
Red Hat Red Hat build of Keycloak 26.4
Default version status: affected
26.4-19 to < *unaffected
Red Hat Red Hat build of Keycloak 26.4
Default version status: affected
26.4-19 to < *unaffected
Red Hat Red Hat build of Keycloak 26.4.13
Default version status: unaffected
Red Hat Red Hat build of Keycloak 26.6
Default version status: affected
26.6.3-3 to < *unaffected
Red Hat Red Hat build of Keycloak 26.6
Default version status: affected
26.6-6 to < *unaffected
Red Hat Red Hat build of Keycloak 26.6
Default version status: affected
26.6-6 to < *unaffected
Red Hat Red Hat build of Keycloak 26.6.3
Default version status: unaffected
References
- https://access.redhat.com/errata/RHSA-2026:25097 ↗
- https://access.redhat.com/errata/RHSA-2026:25098 ↗
- https://access.redhat.com/errata/RHSA-2026:30049 ↗
- https://access.redhat.com/errata/RHSA-2026:30050 ↗
- https://access.redhat.com/security/cve/CVE-2026-9801 ↗
- https://bugzilla.redhat.com/show_bug.cgi?id=2482473 ↗