CVE-2026-96447
Keycloak-services: keycloak-services: stateless token preferred_username fallback enables identity rebinding
What happened?
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.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| keycloak-servicesRed Hat | Default status: unaffected | See vendor advisory |
| rhbk/keycloak-rhel9Red Hat | Default status: unaffected | See vendor advisory |
| keycloak-servicesRed Hat | Default status: unaffected | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.