Vulnerability in Red Hat Build of Keycloak

[ Description ]Official description

A flaw was found in the User Session Note mapper of the Keycloak identity and access management solution. The issue occurs because the mapper does not validate whether a requested session note contains sensitive internal credentials, such as federated access tokens from external identity providers. This allows a delegated client administrator to leak a user's upstream bearer tokens into the tokens issued to their managed application, potentially leading to unauthorized access to the user's data on external platforms.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund4 Oct 2026WID-SEC-2026-3727

  Keycloak: Multiple vulnerabilities Translated from German

  CVE-2026-105302CVE-2026-105301CVE-2026-105306

[ References ]References

• access.redhat.com/security/cve/CVE-2026-105302
• bugzilla.redhat.com/show_bug.cgi