# CVE-2026-96447: Keycloak-services: keycloak-services: stateless token preferred_username fallback enables identity rebinding

Status: published. Published: 2026-11-06. Updated: 2026-11-06.

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.

## Remediation

- 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. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Build of Keycloak (keycloak-services): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Build of Keycloak (rhbk/keycloak-rhel9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Single Sign-On 7 (keycloak-services): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 4.2 (medium); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-287

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2026-96447 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2539288 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-96447; retrieved 2026-11-06; source updated 2026-11-06

Revision: 064b6088061d0fd3bb8167fd20ba5f7966567bb054d479462a5046a6e665ce3c

Canonical: https://y2.dev/cve/CVE-2026-96447

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