diff --git a/C4/Auth.pm b/C4/Auth.pm
index b5308ae4a4..7f0475b16f 100644
--- a/C4/Auth.pm
+++ b/C4/Auth.pm
@@ -195,7 +195,7 @@ sub get_template_and_user {
         $in->{query}->param( -name => 'koha_login_context', -values => ['sco'] );
     } else {
         my $request_method = $in->{query}->request_method // q{};
-        unless ( $request_method eq 'POST' && $in->{query}->param('op') eq 'cud-login' ) {
+        unless ( $request_method eq 'POST' && $in->{query}->param('login_op') eq 'cud-login' ) {
             for my $v (qw( login_userid login_password )) {
                 $in->{query}->param( $v, '' )
                     if $in->{query}->param($v);
@@ -1415,6 +1415,7 @@ sub checkauth {
             $uri->query_param_delete('login_userid');
             $uri->query_param_delete('login_password');
             $uri->query_param_delete('koha_login_context');
+            $uri->query_param_delete('login_op');
             $uri->query_param_delete('op');
             $uri->query_param_delete('csrf_token');
             unless ( $params->{do_not_print} ) {
diff --git a/C4/InstallAuth.pm b/C4/InstallAuth.pm
index 8c84b532cb..55f59f6114 100644
--- a/C4/InstallAuth.pm
+++ b/C4/InstallAuth.pm
@@ -111,7 +111,7 @@ sub get_template_and_user {
     my $template  = C4::Templates->new( $interface, $filename, $tmplbase, $query );
 
     my $request_method = $in->{query}->request_method // q{};
-    unless ( $request_method eq 'POST' && $in->{query}->param('op') eq 'cud-login' ) {
+    unless ( $request_method eq 'POST' && $in->{query}->param('login_op') eq 'cud-login' ) {
         $in->{query}->param( 'login_userid',   '' );
         $in->{query}->param( 'login_password', '' );
     }
diff --git a/Koha/Middleware/CSRF.pm b/Koha/Middleware/CSRF.pm
index fd62c7c7c0..6d084cefe1 100644
--- a/Koha/Middleware/CSRF.pm
+++ b/Koha/Middleware/CSRF.pm
@@ -68,7 +68,7 @@ sub call {
         # Get the CSRF token from the param list or the header
         my $csrf_token = $req->param('csrf_token') || $req->header('CSRF-TOKEN');
 
-        if ( defined $req->param('op') && $original_op !~ m{^cud-} ) {
+        if ( ( defined $req->param('op') && $original_op !~ m{^cud-} ) && !$req->param('login_op') ) {
             $error = sprintf "Programming error - op '%s' must start with 'cud-' for %s %s (referer: %s)", $original_op,
                 $request_method, $uri, $referer;
         } elsif ( !$csrf_token ) {
diff --git a/catalogue/search.pl b/catalogue/search.pl
index 957a9f9dcf..53ec963579 100755
--- a/catalogue/search.pl
+++ b/catalogue/search.pl
@@ -264,7 +264,7 @@ $template->param( advancedsearchesloop => $advancedsearchesloop );
 $template->param( searchid => scalar $cgi->param('searchid'), );
 
 my $default_sort_by     = C4::Context->default_catalog_sort_by;
-my @sanitized_operators = grep { $_ ne 'cud-login' } $cgi->multi_param('op');
+my @sanitized_operators = $cgi->multi_param('op');                #NOTE: No longer sanitized...
 
 # The following should only be loaded if we're bringing up the advanced search template
 if ( $template_type eq 'advsearch' ) {
diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/auth.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/auth.tt
index 7f3ab66202..7fde54a257 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/auth.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/auth.tt
@@ -160,10 +160,9 @@
 
             <form action="[% script_name | html %]" method="post" name="loginform" id="loginform" class="validated">
                 [% INCLUDE 'csrf-token.inc' %]
-                <input type="hidden" name="op" value="cud-login" />
+                <input type="hidden" name="login_op" value="cud-login" />
                 <input type="hidden" name="koha_login_context" value="intranet" />
                 [% FOREACH INPUT IN INPUTS %]
-                    [% NEXT IF INPUT.name == "op" %]
                     [% NEXT IF INPUT.name == "csrf_token" %]
                     [% NEXT IF INPUT.name == "koha_login_context" %]
                     [% NEXT IF INPUT.name == "branch" %]
@@ -254,10 +253,9 @@
         [% ELSIF TwoFA_prompt %]
             <form action="[% script_name | html %]" method="post" name="loginform" id="loginform" autocomplete="off">
                 [% INCLUDE 'csrf-token.inc' %]
-                <input type="hidden" name="op" value="cud-login" />
+                <input type="hidden" name="login_op" value="cud-login" />
                 <input type="hidden" name="koha_login_context" value="intranet" />
                 [% FOREACH INPUT IN INPUTS %]
-                    [% NEXT IF INPUT.name == "op" %]
                     [% NEXT IF INPUT.name == "csrf_token" %]
                     [% NEXT IF INPUT.name == "koha_login_context" %]
                     [% NEXT IF INPUT.name == "branch" %]
diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/installer/auth.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/installer/auth.tt
index d609f9cdc8..96cd6c3cf4 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/installer/auth.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/installer/auth.tt
@@ -57,9 +57,8 @@
 
                 <form action="[% url | html %]" method="post" id="mainform">
                     [% INCLUDE 'csrf-token.inc' %]
-                    <input type="hidden" name="op" value="cud-login" />
+                    <input type="hidden" name="login_op" value="cud-login" />
                     [% FOREACH INPUT IN INPUTS %]
-                        [% NEXT IF INPUT.name == "op" %]
                         [% NEXT IF INPUT.name == "csrf_token" %]
                         [% NEXT IF INPUT.name == "login_userid" %]
                         [% NEXT IF INPUT.name == "login_password" %]
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead.inc b/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead.inc
index 2b6d4478d6..72dcf03814 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead.inc
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead.inc
@@ -508,7 +508,7 @@
                                     [% PROCESS login_label for="muserid" %]<input type="text" id="muserid" name="login_userid" autocomplete="off" /> <label for="mpassword">Password:</label
                                     ><input type="password" id="mpassword" name="login_password" autocomplete="off" />
                                     <fieldset class="action">
-                                        <input type="hidden" name="op" value="cud-login" />
+                                        <input type="hidden" name="login_op" value="cud-login" />
                                         <input type="submit" class="btn btn-primary" value="Log in" />
                                     </fieldset>
                                 </div>
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-auth.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-auth.tt
index a75cd07132..d74c106647 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-auth.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-auth.tt
@@ -236,7 +236,7 @@
                                 [% END %]
                                 <form action="[% form_action | html %]" name="auth" id="auth" method="post" autocomplete="off">
                                     [% INCLUDE 'csrf-token.inc' %]
-                                    <input type="hidden" name="op" value="cud-login" />
+                                    <input type="hidden" name="login_op" value="cud-login" />
                                     <input type="hidden" name="koha_login_context" value="opac" />
 
                                     <div class="local-login">
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-main.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-main.tt
index 84859f99d1..4e4c31416a 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-main.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-main.tt
@@ -202,7 +202,7 @@
                                                 <label for="password">Password:</label>
                                                 <input class="form-control" type="password" id="password" name="login_password" autocomplete="off" />
                                                 <fieldset class="action">
-                                                    <input type="hidden" name="op" value="cud-login" />
+                                                    <input type="hidden" name="login_op" value="cud-login" />
                                                     <input type="submit" value="Log in" class="btn btn-primary" />
                                                 </fieldset>
                                             </div>
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-registration-confirmation.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-registration-confirmation.tt
index 57764dc4a4..83ccf1ec15 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-registration-confirmation.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-registration-confirmation.tt
@@ -110,7 +110,7 @@
                             <form action="/cgi-bin/koha/opac-user.pl" method="post" name="auth" id="auth" autocomplete="off">
                                 [% INCLUDE 'csrf-token.inc' %]
                                 <input type="hidden" name="koha_login_context" value="opac" />
-                                <input type="hidden" name="op" value="cud-login" />
+                                <input type="hidden" name="login_op" value="cud-login" />
                                 <fieldset class="brief">
                                     <legend>Log in to your account:</legend>
                                     [% PROCESS login_label for="userid" %]
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/sco-main.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/sco-main.tt
index 9cd5d9c9cf..e8583f69bd 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/sco-main.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/sco-main.tt
@@ -372,7 +372,7 @@
                                         [% FOREACH INPUT IN INPUTS %]
                                             <input type="hidden" name="[% INPUT.name | html %]" value="[% INPUT.value | html %]" />
                                         [% END %]
-                                        <input type="hidden" name="op" value="cud-login" />
+                                        <input type="hidden" name="login_op" value="cud-login" />
                                     </fieldset>
                                 </form>
                                 <!-- /#mainform -->
diff --git a/opac/opac-tags.pl b/opac/opac-tags.pl
index 70429fda57..603e50b509 100755
--- a/opac/opac-tags.pl
+++ b/opac/opac-tags.pl
@@ -122,7 +122,7 @@ unless ( C4::Context->preference('TagsEnabled') ) {
 
 if ($add_op) {
     unless ($loggedinuser) {
-        push @errors, { +'cud-login' => 1 };
+        push @errors, { +'login' => 1 };
         push @globalErrorIndexes, $#errors;
         %newtags = ();    # zero out any attempted additions
         @deltags = ();    # zero out any attempted deletions