Insufficient Session Expiration
It was found that the cookie used for CSRF prevention in Keycloak was not unique to each session. An attacker could use this flaw to gain access to an authenticated user session, leading to possible information disclosure or further attacks.
CWE-613 - Insufficient Session Expiration
According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization."