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.
https://github.com/discourse/discourse/security/advisories/GHSA-7pm2-prxw-wrvp
https://github.com/discourse/discourse/pull/20009
https://github.com/discourse/discourse/pull/20008
https://github.com/discourse/discourse/commit/c186a46910431020e8efc425dec2133e7a99fa9a
https://github.com/discourse/discourse/commit/1a5a6f66cb821ed29a737311d6fdc2eba5adc915