Provide references for CVE-2018-1000089.
Where can I find more information about CVE-2018-1000089?
References are available at: https://github.com/anymail/django-anymail/commit/1a6086f2b58478d71f89bf27eb034ed81aefe5ef, https://github.com/anymail/django-anymail/releases/tag/v1.4.