CVE-2026-9704

A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subjecttoken JSON Web Token JWT to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client...

CVE-2026-9704: Improper Validation of Specified Quantity in Input

A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subjecttoken JSON Web Token JWT to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client...