Riskcovery

CVE-2026-9801

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

State
Published
Severity
4.9 Medium
Published
May 28, 2026
Updated
Jun 26, 2026
Reserved
May 28, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.14.9 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:Hredhat

Weaknesses

  • CWE-1284 Improper Validation of Specified Quantity in Input

Affected Products

ProductVersions
Red Hat build of Keycloak 26.4Red Hat
  • 26.4.13-1 and laterNot affected
Red Hat build of Keycloak 26.4Red Hat
  • 26.4-19 and laterNot affected
Red Hat build of Keycloak 26.4Red Hat
  • 26.4-19 and laterNot affected
Red Hat build of Keycloak 26.4.13Red Hat
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6.3-3 and laterNot affected
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6-6 and laterNot affected
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6-6 and laterNot affected
    Red Hat build of Keycloak 26.6.3Red Hat

      References

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