CVE-2026-79651
Keycloak-services: keycloak-services: unauthenticated dos via unbounded locale caching
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-400 |
| Vendor | red hat |
| Product | red hat build of keycloak 26.4 |
| Published | Sep 16, 2026 |
| Last Updated | Sep 16, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
Red Hat / Red Hat build of Keycloak 26.4
All versions affected Red Hat / Red Hat build of Keycloak 26.4
All versions affected Red Hat / Red Hat build of Keycloak 26.4
All versions affected Red Hat / Red Hat build of Keycloak 26.4.16
All versions affected Red Hat / Red Hat build of Keycloak 26.4.16
All versions affected Red Hat / Red Hat build of Keycloak 26.4.16
All versions affected Red Hat / Red Hat build of Keycloak 26.6
All versions affected Red Hat / Red Hat build of Keycloak 26.6
All versions affected Red Hat / Red Hat build of Keycloak 26.6
All versions affected Red Hat / Red Hat build of Keycloak 26.6.7
All versions affected Red Hat / Red Hat build of Keycloak 26.6.7
All versions affected Red Hat / Red Hat build of Keycloak 26.6.7
All versions affected Red Hat / Red Hat Single Sign-On 7
All versions affected References
access.redhat.com: https://access.redhat.com/errata/RHSA-2026:68276 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:68277 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:68278 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:68280 access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-79651 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2523345
Credits
Red Hat would like to thank yd1ng for reporting this issue.