Discourse is an open-source messaging platform. In versions 2.8.10 and prior on the stable
branch and versions 2.9.0.beta11 and prior on the beta
and tests-passed
branches, users composing malicious messages and navigating to drafts page could self-XSS. This vulnerability can lead to a full XSS on sites which have modified or disabled Discourseβs default Content Security Policy. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.