diff -up tcp_wrappers_7.6-ipv6.4/hosts_access.c.altformat tcp_wrappers_7.6-ipv6.4/hosts_access.c
--- tcp_wrappers_7.6-ipv6.4/hosts_access.c.altformat	2013-08-15 18:46:30.398827866 +0200
+++ tcp_wrappers_7.6-ipv6.4/hosts_access.c	2013-08-15 18:50:03.099748732 +0200
@@ -326,11 +326,15 @@ struct host_info *host;
 	    if (cbr = strchr(tok, ']'))
 		*cbr = '\0';
 
+	    if (cbr == NULL) {
+		    tcpd_warn("bad IP6 address specification");
+		    return (NO);
+	    }
 	    /*
 	     * A /nnn prefix specifies how many bits of the address we
 	     * need to check. 
 	     */
-	    if (slash = strchr(tok, '/')) {
+	    if ((slash = strchr(tok, '/')) || (slash = strchr(cbr+1, '/'))) {
 		*slash = '\0';
 		mask = atoi(slash+1);
 		if (mask < 0 || mask > IPV6_ABITS) {
diff -up tcp_wrappers_7.6-ipv6.4/tcpdchk.c.altformat tcp_wrappers_7.6-ipv6.4/tcpdchk.c
--- tcp_wrappers_7.6-ipv6.4/tcpdchk.c.altformat	1999-10-28 08:38:06.000000000 +0200
+++ tcp_wrappers_7.6-ipv6.4/tcpdchk.c	2013-08-15 18:46:30.399827870 +0200
@@ -430,6 +430,9 @@ char   *pat;
 	    int err = 0;
 	    int mask = IPV6_ABITS;
 
+	    if (!slash)
+	      slash = strchr(cbr+1, '/');
+
 	    if (slash != NULL) {
 		*slash = '\0';
 		mask = atoi(slash + 1);