CVE-2026-97848

Keycloak-services: keycloak-services: protocol mapper with jsontype=json bypasses token sanitization

Published Nov 6, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in the token sanitization logic of Keycloak, an open source identity and access management solution. The issue occurs when a protocol mapper is configured to emit structured claims using the JSON type. The security check designed to remove unauthorized role mappings only looks for standard Java maps and fails to recognize Jackson based JSON objects. This allows an attacker to inject forged client roles into security tokens, which could lead to unauthorized access to protected resources.

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

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak: cpe:/a:redhat:build_keycloak:26.4::el9
cpe:/a:redhat:build_keycloak:26.6::el9
References
Type Values Removed Values Added
Title keycloak-services: keycloak-services: Protocol mapper with jsonType=JSON bypasses token sanitization Keycloak-services: keycloak-services: protocol mapper with jsontype=json bypasses token sanitization
First Time appeared Redhat
Redhat build Keycloak
Redhat red Hat Single Sign On
CPEs cpe:/a:redhat:build_keycloak:
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat
Redhat build Keycloak
Redhat red Hat Single Sign On
References
Type Values Removed Values Added
Description A flaw was found in the token sanitization logic of Keycloak, an open source identity and access management solution. The issue occurs when a protocol mapper is configured to emit structured claims using the JSON type. The security check designed to remove unauthorized role mappings only looks for standard Java maps and fails to recognize Jackson based JSON objects. This allows an attacker to inject forged client roles into security tokens, which could lead to unauthorized access to protected resources.
Title keycloak-services: keycloak-services: Protocol mapper with jsonType=JSON bypasses token sanitization
Weaknesses CWE-20
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}

threat_severity

Moderate

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 9, 2026, 10:46 PM
Reserved
Sep 25, 2026, 6:24 AM
Status
Awaiting Analysis
Published
Nov 6, 2026, 6:16 AM
Modified
Nov 9, 2026, 11:17 PM
Severity
Moderate
Public date
Nov 5, 2026, 12:00 AM