An issue was discovered in Django 1.11.x before 1.11.23, 2.1.x before 2.1.11, and 2.2.x before 2.2.4. Due to the behaviour of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.
An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.
An issue was discovered in Django 1.11 before 1.11.21, 2.1 before 2.1.9, and 2.2 before 2.2.2. The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, an unvalidated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.
Django 1.11.x before 1.11.19, 2.0.x before 2.0.11, and 2.1.x before 2.1.6 allows Uncontrolled Memory Consumption via a malicious attacker-supplied value to the django.utils.numberformat.format() function.
In Django 1.11.x before 1.11.18, 2.0.x before 2.0.10, and 2.1.x before 2.1.5, an Improper Neutralization of Special Elements in Output Used by a Downstream Component issue exists in django.views.defaults.page_not_found(), leading to content spoofing (in a 404 error page) if a user fails to recognize that a crafted URL has malicious content.