CVE-2026-9801CWE-1284

Keycloak: keycloak: denial of service via malformed ldap password policy response

Medium · published May 28, 2026

CVSS v3.1
4.9
EPSS
1%
Percentile
59.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.9 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00895 · 59.1th percentile
Weakness
CWE-1284 · Improper Validation of Specified Quantity in Input
Published
2026-05-28T04:42Z
EPSS history
Timeline
  • 28 MAY 04:42Z
    Keycloak: keycloak: denial of service via malformed ldap password policy response
    cvelistv5