CVE-2018-20859
edx-platform before 2018-07-18 allows XSS via a response to a Chemical Equation advanced problem.
Date published : 2019-07-30
https://github.com/edx/edx-platform/commit/5b144559fbdba7ff673cc1c165aa2d343e07b6bd.patch
https://groups.google.com/forum/#%21topic/openedx-announce/wsm5mtUhhME