Medium · published October 19, 2026
The ForgeRock client fails to correctly validate refresh tokens. This allows a refresh token to be treated as a valid access token, enabling its use for consuming protected resources. This bypasses the intended security control that requires valid client credentials in addition to a refresh token to obtain a new access token.
An attacker who obtains a stolen or exposed refresh token can leverage this vulnerability to directly access protected resources. This is possible because the standard security flow requiring client credentials to exchange a refresh token for an access token is circumvented.