EDIT

            // check for subtree permissions as well.

            TaxonBase<?> taxonBase = (TaxonBase<?>)getInput();

            Taxon acceptedTaxon = null;

            if (taxonBase instanceof Taxon){

                acceptedTaxon = (Taxon)taxonBase;

            }else{

                acceptedTaxon = ((Synonym)taxonBase).getAcceptedTaxon();

            }

            if (acceptedTaxon != null){ //needs discussion if synonyms without accepted taxon should never be filtered by subtree permission(current implementation). See also #8849

                Set<TaxonNode> nodes = acceptedTaxon.getTaxonNodes();

                for (TaxonNode node: nodes){

                    hasPermission &= CdmStore.currentAuthentiationHasPermission(node, requiredCrud);

                    if (!hasPermission){

                        //check whether there are explicit TaxonNode rights

                        boolean taxonnodePermissionExists = false;

                        Collection<? extends GrantedAuthority> authorities = CdmStore.getCurrentAuthentiation().getAuthorities();

                        for (GrantedAuthority grantedAuthority: authorities){

                            if (grantedAuthority.getAuthority().startsWith("TAXONNODE")){

                                taxonnodePermissionExists = true;

                            }

                        }

                        if (!taxonnodePermissionExists){

                            hasPermission = true;