SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-9801

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.

MEDIUM 4.9EPSS 0.48%

Does this matter?

Lower severity and a low EPSS score (0.48%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
4.9 MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS
0.48% probability · 40th percentile
CISA KEV
Not listed
Weakness
CWE-1284
Affected
redhat/build of keycloak
Source
secalert@redhat.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.