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.

  • Published Sep 25, 2026
  • CVSS 6.8 medium
  • 0.1% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-97846 at the National Vulnerability Database