High

Allocation of Resources Without Limits in Keycloak

  • Disclosed: 14.12.2023
  • Updated: 11.10.2026 11:22

An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (> 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the "consents" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system.

Affected software

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PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) org.keycloak:keycloak-model-jpa < 21.0.0 21.0.0

References

CVSS score 7.7/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Weakness (CWE)
CWE-770
Platform
Java / Kotlin (Maven)
Package
org.keycloak:keycloak-model-jpa
Disclosed
14.12.2023
Updated
11.10.2026 11:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-54f3-c6hg-865h - CC BY 4.0

Vulnerability history: org.keycloak:keycloak-model-jpa

All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
3
First → latest
05.2022 03.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 2
  • Medium 1

Disclosures per year

  1. 2022: 1
  2. 2023: 1
  3. 2024: 0
  4. 2025: 0
  5. 2026: 1
  1. Allocation of Resources Without Limits in Keycloak this entry
    High · 7.7 CVE-2023-6563 < 21.0.0 21.0.0
  2. High · 7.5 CVE-2019-14832 < 7.0.1 7.0.1

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