CVE-2026-97846

Keycloak provides a feature called mTLS holder-of-key binding which ensures that a token can only be used by the client that originally requested it by binding it to their digital certificate. A flaw was discovered where the new Standard Token Exchange V2 feature does not check for this certificate. This allows an attacker with stolen client credentials to obtain a standard, unrestricted token that bypasses these security protections.

Score

CVSS 3.1 6.8 Medium

Status

Awaiting Analysis - secalert@redhat.com

Published

2026-09-25

Last modified

2026-09-25

Weaknesses

CWE-287

Affected products

• Build Keycloak (Redhat)
• Red Hat Single Sign On (Redhat)

References

• https://access.redhat.com/security/cve/CVE-2026-97846
• https://bugzilla.redhat.com/show_bug.cgi?id=2540949