[SECURITY] Fix reflected XSS in redirection page (CVE-2026-57533)

src/pretix/base/templates/pretixbase/redirect.html

@@ -2,13 +2,14 @@
 {% load i18n %}
 {% load rich_text %}
 {% load static %}
+{% load wrap_in %}
 {% block title %}{% trans "Redirect" %}{% endblock %}
 {% block content %}
 <i class="fa fa-link fa-fw big-icon"></i>
 <div class="error-details">
     <h1>{% trans "Redirect" %}</h1>
     <h3>
-        {% blocktrans trimmed with host="<strong>"|add:hostname|add:"</strong>"|safe %}
+        {% blocktrans trimmed with host=hostname|wrap_in:'strong' %}
         The link you clicked on wants to redirect you to a destination on the website {{ host }}.
         {% endblocktrans %}
         {% blocktrans trimmed %}

src/pretix/helpers/templatetags/wrap_in.py

@@ -0,0 +1,33 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020  Raphael Michel and contributors
+# Copyright (C) 2020-today pretix GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+import logging
+
+from django import template
+from django.utils.html import format_html
+
+register = template.Library()
+logger = logging.getLogger(__name__)
+
+
+@register.filter
+def wrap_in(content, tag_name):
+    return format_html(f'<{tag_name}>{{}}</{tag_name}>', content)