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High severityNVD Advisory· Published Jul 20, 2020· Updated Aug 4, 2024

Cross-Site Scripting in Wagtail

CVE-2020-15118

Description

In Wagtail before versions 2.7.4 and 2.9.3, when a form page type is made available to Wagtail editors through the wagtail.contrib.forms app, and the page template is built using Django's standard form rendering helpers such as form.as_p, any HTML tags used within a form field's help text will be rendered unescaped in the page. Allowing HTML within help text is an intentional design decision by Django; however, as a matter of policy Wagtail does not allow editors to insert arbitrary HTML by default, as this could potentially be used to carry out cross-site scripting attacks, including privilege escalation. This functionality should therefore not have been made available to editor-level users. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin. Patched versions have been released as Wagtail 2.7.4 (for the LTS 2.7 branch) and Wagtail 2.9.3 (for the current 2.9 branch). In these versions, help text will be escaped to prevent the inclusion of HTML tags. Site owners who wish to re-enable the use of HTML within help text (and are willing to accept the risk of this being exploited by editors) may set WAGTAILFORMS_HELP_TEXT_ALLOW_HTML = True in their configuration settings. Site owners who are unable to upgrade to the new versions can secure their form page templates by rendering forms field-by-field as per Django's documentation, but omitting the |safe filter when outputting the help text.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
wagtailPyPI
>= 2.8rc1, < 2.9.32.9.3
wagtailPyPI
< 2.7.42.7.4

Affected products

1

Patches

1
d9a41e7f24d0

Escape help text in form builder forms by default

https://github.com/wagtail/wagtailMatt WestcottJul 9, 2020via ghsa
commit
4 files changed · +29 −1
  • docs/reference/settings.rst+13 −0 modified
    @@ -547,3 +547,16 @@ By default the redirect importer keeps track of the uploaded file as a temp file
 .. code-block:: python
 
    WAGTAIL_REDIRECTS_FILE_STORAGE = 'cache'
+
+Form builder
+============
+
+.. versionadded:: 2.7.4/2.9.3
+
+    The ``WAGTAILFORMS_HELP_TEXT_ALLOW_HTML`` option was added.
+
+.. code-block:: python
+
+    WAGTAILFORMS_HELP_TEXT_ALLOW_HTML = True
+
+When true, HTML tags in form field help text will be rendered unescaped (default: False).
  • wagtail/contrib/forms/forms.py+6 −1 modified
    @@ -1,6 +1,8 @@
 from collections import OrderedDict
 
 import django.forms
+from django.conf import settings
+from django.utils.html import conditional_escape
 from django.utils.translation import gettext_lazy as _
 
 from wagtail.admin.forms import WagtailAdminPageForm
@@ -114,7 +116,10 @@ def formfields(self):
     def get_field_options(self, field):
         options = {}
         options['label'] = field.label
-        options['help_text'] = field.help_text
+        if getattr(settings, 'WAGTAILFORMS_HELP_TEXT_ALLOW_HTML', False):
+            options['help_text'] = field.help_text
+        else:
+            options['help_text'] = conditional_escape(field.help_text)
         options['required'] = field.required
         options['initial'] = field.default_value
         return options
  • wagtail/contrib/forms/tests/test_models.py+9 −0 modified
    @@ -29,9 +29,18 @@ def test_get_form(self):
         self.assertTemplateUsed(response, 'tests/form_page.html')
         self.assertTemplateNotUsed(response, 'tests/form_page_landing.html')
 
+        # HTML in help text should be escaped
+        self.assertContains(response, "&lt;em&gt;please&lt;/em&gt; be polite")
+
         # check that variables defined in get_context are passed through to the template (#1429)
         self.assertContains(response, "<p>hello world</p>")
 
+    @override_settings(WAGTAILFORMS_HELP_TEXT_ALLOW_HTML=True)
+    def test_get_form_without_help_text_escaping(self):
+        response = self.client.get('/contact-us/')
+        # HTML in help text should not be escaped
+        self.assertContains(response, "<em>please</em> be polite")
+
     def test_post_invalid_form(self):
         response = self.client.post('/contact-us/', {
             'your_email': 'bob',
  • wagtail/contrib/forms/tests/utils.py+1 −0 modified
    @@ -28,6 +28,7 @@ def make_form_page(**kwargs):
         label="Your message",
         field_type='multiline',
         required=True,
+        help_text="<em>please</em> be polite"
     )
     FormField.objects.create(
         page=form_page,

Vulnerability mechanics

Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

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