CVE-2026-9801

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

4.9CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS

0.5% chance of exploitation in the next 30 days; higher than 40% of CVEs (scores of 2026-10-25)

CWE

CWE-1284

Published

2026-05-28

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• redhat:build_of_keycloak

Packages (OSV)

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

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