A flaw was found in the theme localization endpoints of the keycloak-services component, which is the core service responsible for authentication flows and theme management in Keycloak. The issue occurs because the system accepts arbitrary locale tags from unauthenticated requests and stores them in a permanent in-memory cache without limits. An attacker can exploit this by sending a large number of unique locale tags, eventually causing the server to run out of memory and crash.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 6
https://access.redhat.com/security/cve/CVE-2026-79651
secalert@redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2523345
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:68276
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:68277
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:68278
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:68280
secalert@redhat.com