VULNERABILITY INTELLIGENCE

CVE-2023-6563

CVSS score7.7 HIGH
EPSS probability1.24%
CISA KEVNot currently listed
Published2023-12-14
Last modified2026-09-22
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Description

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.

Weakness classification

  • CWE-770: Allocation of Resources Without Limits or Throttling

Primary references