8.1
High
CVE-2026-11800 A flaw was found in Keycloak
Description
A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an attacker with valid client credentials to bypass signature verification. By forging an assertion, the attacker can create unauthorized access tokens. This enables the attacker to impersonate any federated user linked to the affected Identity Provider, leading to unauthorized access and potential privilege escalation.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat build of Keycloak 26.6 26.6 | earliest → < 26.6-8 | 26.6-8 |
| Red Hat build of Keycloak 26.6.4 | Versions not published | |
| Red Hat Build of Keycloak | Versions not published | |
| Red Hat Data Grid 8 | Versions not published | |
| Red Hat JBoss Enterprise Application Platform Expansion Pack | Versions not published | |
| Red Hat Single Sign-On 7 | Versions not published |
References
- RHSA-2026:30083 access.redhat.com
- RHSA-2026:30084 access.redhat.com
- access.redhat.com access.redhat.com
- RHBZ#2487006 bugzilla.redhat.com
Timeline
- Published
- Last modified
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