diff --git a/C4/Auth.pm b/C4/Auth.pm
index 164092d01e..23311f0083 100644
--- a/C4/Auth.pm
+++ b/C4/Auth.pm
@@ -139,6 +139,9 @@ sub get_template_and_user {
     my $in       = shift;
     my ( $user, $cookie, $sessionID, $flags );
 
+    my $safe_chars = 'a-zA-Z_\-\/';
+    die "bad template path" unless $in->{'template_name'} =~ m/^[$safe_chars]+.tt?$/ig; #sanitize input
+
     $in->{'authnotrequired'} ||= 0;
     my $template = C4::Templates::gettemplate(
         $in->{'template_name'},