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CVE-2026-9801

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

Published: May 28, 2026Updated: Jun 26, 2026 Sources: CVE List NVDCWE-1284
4.9MEDIUM
NVD MITRE
EPSS Score
0.5%
Top 61.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:HUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:HPrivileges Required
High
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-1284

Affected Products

Red Hat
commercial·USaka redhat
Red Hat build of Keycloak 26.4On-premWeb App
Web & CMS Plugins
Red Hat build of Keycloak 26.4.13On-prem
DevTools & CI
Red Hat build of Keycloak 26.6On-prem
Security Products / identity-access-mgmt
Red Hat build of Keycloak 26.6.3On-prem
Security Products / identity-access-mgmt
build of keycloakOn-prem
Operating Systems / linux-distro

Exploitability

Official Patch Available
Workaround Available
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References

https://access.redhat.com/errata/RHSA-2026:25097
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:25098
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:30049
access.redhat.com
and 3 more references View all →

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