CVE-2026-18569
Keycloak-services: keycloak-services: oidc backchannel logout accepts unsigned forged logout tokens
- State
- Published
- Severity
- 3.7 Low
- Published
- Aug 4, 2026
- Updated
- Aug 31, 2026
- Reserved
- Aug 2, 2026
Description
A flaw was found in the backchannel logout endpoint of the keycloak-services component, which is part of the Red Hat Build of Keycloak. This component handles authentication and session management for applications. The issue occurs when an OIDC identity provider is configured to skip signature validation. In this specific setup, the system incorrectly accepts logout requests that have no cryptographic signature. An attacker who knows certain technical details about a user's session can use this flaw to force that user to be logged out, potentially disrupting their work.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 3.7 Low | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L | redhat |
Weaknesses
- CWE-347 Improper Verification of Cryptographic Signature
Affected Products
| Product | Versions |
|---|---|
Red Hat Build of KeycloakRed Hat | |
Red Hat Build of KeycloakRed Hat | |
Red Hat Build of KeycloakRed Hat | |
Red Hat Data Grid 8Red Hat | |
Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat | |
Red Hat Single Sign-On 7Red Hat |
References
- https://access.redhat.com/security/cve/CVE-2026-18569vdb-entry
- RHBZ#2509755issue-tracking
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