# UNDF: UNDF-2026-000001141
# UNDF:
--- a/libpurple/privacy.c
+++ b/libpurple/privacy.c
@@ -231,18 +231,24 @@ static void
 add_all_buddies_to_permit_list(PurpleAccount *account, gboolean local)
 {
 	GSList *list;
+	GHashTable *permit_set;
+	GSList *permit_iter;

 	/* Remove anyone in the permit list who is not in the buddylist */
 	for (list = account->permit; list != NULL; ) {
 		char *person = list->data;
 		list = list->next;
 		if (!purple_find_buddy(account, person))
 			purple_privacy_permit_remove(account, person, local);
 	}

+	/* Build a hash set of existing permit names for O(1) membership test */
+	permit_set = g_hash_table_new(g_str_hash, g_str_equal);
+	for (permit_iter = account->permit; permit_iter != NULL; permit_iter = permit_iter->next)
+		g_hash_table_add(permit_set, permit_iter->data);
+
 	/* Now make sure everyone in the buddylist is in the permit list */
 	list = purple_find_buddies(account, NULL);
 	while (list != NULL)
 	{
 		PurpleBuddy *buddy = list->data;
 		const gchar *name = purple_buddy_get_name(buddy);

-		if (!g_slist_find_custom(account->permit, name, (GCompareFunc)g_utf8_collate))
+		if (!g_hash_table_lookup(permit_set, name))
 			purple_privacy_permit_add(account, name, local);
 		list = g_slist_delete_link(list, list);
 	}
+
+	g_hash_table_destroy(permit_set);
 }