4.2
Medium
CVE-2026-96447 Keycloak-services: keycloak-services: stateless token preferred_username fallback enables identity rebinding
Description
A flaw was found in the TokenManager component of Keycloak, an open-source identity and access management solution. The issue occurs during the validation of stateless access tokens when the original user ID no longer exists. Keycloak incorrectly falls back to using the username to identify the user without verifying if the identity matches the original token subject. This could allow an attacker with an old token to gain access to a newly created service account if it shares the same client ID as a previously deleted one.
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:NExploitable remotely over the network, with an ordinary account and without any user action; the impact on data or service is limited.
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Build of Keycloak | Versions not published | |
| Red Hat Single Sign-On 7 | Versions not published | |
| Red Hat build of Keycloak 26.6.8 | Versions not published | |
| Red Hat build of Keycloak 26.6 26.6 | earliest → < 26.6-24 | 26.6-24 |
Other CVEs of Red Hat Build of Keycloak
The 276 CVEs of Red Hat Build of Keycloak →
CVE-2026-9797
Keycloak: keycloak: privilege escalation via client authentication manipulation by an authenticated administrator
6.5
Medium
CVE-2026-97848
Keycloak-services: keycloak-services: protocol mapper with jsontype=json bypasses token sanitization
6.5
Medium
CVE-2026-97367
Keycloak-services: keycloak-services: dcr azp and sid claim substitution allows account rest session takeover
6.4
Medium
CVE-2026-96547
Keycloak-services: keycloak-services: dcr registration-time claim-path gap allows forging realm_access.roles
6.5
Medium