CVE-2026-9801: Red Hat Build Of Keycloak

Medium severity, CVSS 4.9. EPSS: 0.9% chance of exploitation in the next 30 days.

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

• Red Hat Build Of Keycloak: affected versions not specified

Published 2026-05-28. Last modified 2026-06-26.