CVE-2026-79651 vulnerability in Red Hat Products
Published on September 16, 2026
Keycloak-services: keycloak-services: unauthenticated dos via unbounded locale caching
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.
Vulnerability Analysis
CVE-2026-79651 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Timeline
Reported to Red Hat.
Made public. 26 days later.
Weakness Type
What is a Resource Exhaustion Vulnerability?
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
CVE-2026-79651 has been classified to as a Resource Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-79651
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Affected Versions
Red Hat build of Keycloak 26.4:- Version 26.4-26 and below * is unaffected.
- Version 26.4-26 and below * is unaffected.
- Version 26.4.16-2 and below * is unaffected.
- Version 26.6-20 and below * is unaffected.
- Version 26.6.7-3 and below * is unaffected.
- Version 26.6-20 and below * is unaffected.