CVE-2026-9801 — Keycloak: keycloak: denial of service via malformed ldap password policy response
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 o…
Published: 2026-05-28 · CVSS: 4.9 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7