Keycloak-services: keycloak-services: unauthenticated dos via unbounded locale caching
Summary
| CVE | CVE-2026-79651 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-16 15:17:52 UTC |
| Updated | 2026-09-16 19:42:43 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Problem Types: CWE-400 | CWE-400 Uncontrolled Resource Consumption
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4 | unaffected 26.4.16-2 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4 | unaffected 26.4-26 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4 | unaffected 26.4-26 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4.16 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4.16 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4.16 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6 | unaffected 26.6.7-3 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6 | unaffected 26.6-20 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6 | unaffected 26.6-20 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6.7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6.7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6.7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Single Sign-On 7 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| access.redhat.com/errata/RHSA-2026:68278 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:68280 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:68276 | [email protected] | access.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-79651 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:68277 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank yd1ng for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-08-21T10:24:34.000Z | Reported to Red Hat. |
| CNA | 2026-09-16T13:18:07.000Z | Made public. |
Workarounds
CNA: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
There are currently no legacy QID mappings associated with this CVE.