CVE-2026-9801 (GCVE-0-2026-9801)

Vulnerability from cvelistv5 – Published: 2026-05-28 04:42 – Updated: 2026-05-30 01:54
VLAI
Title
Keycloak: keycloak: denial of service via malformed ldap password policy response
Summary
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.
Severity
4.9 (Medium)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-1284 - Improper Validation of Specified Quantity in Input
Assigner
References
URL Tags
https://access.redhat.com/security/cve/CVE-2026-9801 vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2482473 issue-trackingx_refsource_REDHAT
Impacted products
Vendor Product Version
Red Hat Red Hat Build of Keycloak     cpe:/a:redhat:build_keycloak:
 Create a notification for this product.
Date Public
2026-05-28 04:18
Credits
Red Hat would like to thank Seongkuk Park for reporting this issue.
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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