CVE-2026-18569

Keycloak-services: keycloak-services: oidc backchannel logout accepts unsigned forged logout tokens

Published Aug 4, 2026 CVSS 3.1 · 3.7 Low EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Workaround

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.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak: cpe:/a:redhat:build_keycloak:26.6::el9
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title keycloak-services: keycloak-services: OIDC backchannel logout accepts unsigned forged logout tokens Keycloak-services: keycloak-services: oidc backchannel logout accepts unsigned forged logout tokens
First Time appeared Redhat build Keycloak
Redhat jboss Data Grid
Redhat jbosseapxp
Redhat red Hat Single Sign On
CPEs cpe:/a:redhat:build_keycloak:
cpe:/a:redhat:jboss_data_grid:8
cpe:/a:redhat:jbosseapxp
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat build Keycloak
Redhat jboss Data Grid
Redhat jbosseapxp
Redhat red Hat Single Sign On
References
Type Values Removed Values Added
First Time appeared Redhat
Redhat keycloak
Vendors & Products Redhat
Redhat keycloak
Type Values Removed Values Added
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.
Title keycloak-services: keycloak-services: OIDC backchannel logout accepts unsigned forged logout tokens
Weaknesses CWE-347
References
Metrics threat_severity

None

cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Low

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 7, 2026, 11:52 AM
Reserved
Aug 2, 2026, 5:15 AM
Status
Modified
Published
Aug 4, 2026, 6:16 AM
Modified
Nov 7, 2026, 12:17 PM
Severity
Low
Public date
Jul 31, 2026, 10:18 AM