Discourse is an open-source discussion platform. Prior to version 3.0.1 of the stable
branch and version 3.1.0.beta2 of the beta
and tests-passed
branches, a maliciously crafted URL can be included in a user's full name field to to carry out cross-site scripting attacks on sites with a disabled or overly permissive CSP (Content Security Policy). Discourse's default CSP prevents this vulnerability. The vulnerability is patched in version 3.0.1 of the stable
branch and version 3.1.0.beta2 of the beta
and tests-passed
branches. As a workaround, enable and/or restore your site's CSP to the default one provided with Discourse.