--- cdrkit/genisoimage/genisoimage.c

+++ cdrkit/genisoimage/genisoimage.c

@@ -3406,7 +3406,7 @@ if (check_session == 0)

 	if (goof) {

 		fprintf(stderr, "ISO9660/Rock Ridge tree sort failed.\n");

 		if(merge_warn_msg)

-			fprintf(stderr, merge_warn_msg);

+			fprintf(stderr, "%s", merge_warn_msg);

 		exit(1);

 	}

 #ifdef UDF

@@ -3419,7 +3419,7 @@ if (check_session == 0)

 	if (goof) {

 		fprintf(stderr, "Joliet tree sort failed. The -joliet-long switch may help you.\n");

 		if(merge_warn_msg)

-			fprintf(stderr, merge_warn_msg);

+			fprintf(stderr, "%s", merge_warn_msg);

 		exit(1);

 	}

 	/*

--- cdrkit/genisoimage/tree.c

+++ cdrkit/genisoimage/tree.c

@@ -647,7 +647,7 @@ got_valid_name:

      fprintf(stderr, "Unable to sort directory %s\n",

            this_dir->whole_name);

      if(merge_warn_msg)

-        fprintf(stderr, merge_warn_msg);

+        fprintf(stderr, "%s", merge_warn_msg);

      exit(1);

 	}

 	/*